TOEFL junior模拟试题

TOEFL junior模拟试题
TOEFL junior模拟试题

Listening Comprehension

The listening section has 33 questions. Follow along as you listen to the directions to the listening section.

Directions

In this section of the test, you will hear a teacher or other school staff member talking to students. Each talk is followed by one question. Choose the best answer to each question and mark the letter of the correct answer on your answer sheet. You will hear each talk only one time.

Here is an example:

What does the teacher want the students to do?

(A)Help a new classmate.

(B) Tell the students to be careful.

(C) Let his student to celebrate the new classmate.

(D) She thinks vanilla is the best flavor of ice cream.

The correct answer is (A), “Help a new classmate.”

Here is another example:

What will the girl probably do next?

(A) Buy a new dictionary

(B) Listen to some music

(C) Write her name in the dictionary

(D) Help the boy find his dictionary

The correct answer is (B), “ Listen to some music”

Go on to the next page, and the test will begin with question number one.

1. What is the purpose of the talk?

(A) To introduce how to make a design for a poster

(B) To make the poster more colorful

(C) To give some instructions of making a real poster

(D) To ask students to do a real design and poster together

2. What does the teacher ask the students to do?

(A) Not to forget to learn the relationship between the economy and sailing ships

(B) Remember to make an economical sailing ship

(C) Inquire about the relationship between the economy and sailing ships after class

(D) Read a novel about the relationship between the economy and sailing ships

3. Why is the principal addressing the students?

(A) To encourage students to buy breakfast every day in order to be energetic

(B) To ask students living far away from the campus not to be late next time

(C) To tell students that the breakfast will be better and better

(D) To inform students of a change of the cafeteria where they have the breakfast

4. What is probably true about the present parking lot?

(A) It is not large enough for all cars.

(B) It is often occupied by students living off-campus.

(C) It is often used by students from other school.

(D) It is going to be enlarged in a few days.

5. What will the teacher probably talk about next?

(A) The relationship between mice and cats

(B) The response of the mice who stay still

(C) The color of the mice who did not move

(D) The concept of fearfulness

6. What is the purpose of the announcement made by the principal?

(A) To ask students never play soccer again

(B) To encourage students to play soccer to improve the reputation of the school

(C) To require students change the place of some activities (D) To remind students of the improved impression of visitors

7. What is probably true about the students learning science in the lecture?

(A) They are eager to learn the artesian spring.

(B) They will have a test on artesian spring.

(C) They probably have learned something about artesian spring.

(D) They are going to draw a picture of the artesian spring.

8. What is probably true about the students who keep moving out of the dormitories?

(A) They think it is expensive to live in dormitories.

(B) They are likely to move out of dormitories for fun.

(C) They cannot accept the old beds and shelves in dormitories.

(D) They are going to buy new lights, shelves and beds in two years.

9. Why is the principal addressing the students?

(A) To give students some good news

(B) To ask students not to go to the cafeteria again

(C) To tell students a change of the tables in the classroom

(D) To encourage students to repair tables in the Student Center cafeteria

10. What will the teacher probably do next?

(A) Compare dogs with other animals

(B) Write something on the blackboard to explain the structure of other birds

(C) Ask students to explain why falcons fly so fast

(D) Draw a beautiful picture of the falcon on the blackboard

Now you will hear some conversations.Each conversation is followed by three or more questions. Choose the best answer to each question and mark the letter of the correct answer on your answer sheet. You will hear each conversation only one time.

11. What problem does the man have?

(A) The library assistant thinks he has an overdue book.

(B) The books he needs have been checked out by someone else.

(C) The library assistant is unable to locate the books that he needs.

(D) A library notice was sent to him at his previous address.

12. Why does the man mention that he is a new student at the school?

(A) To explain why he had difficulty finding the library.

(B) To explain why he couldn't have borrowed library books in June.

(C) To explain why he doesn't yet have a library card.

(D) To explain why he needs assistance in locating a book.

13. What does the woman discover when she looks up the records on her computer?

(A) The man has mistakenly received someone else's books.

(B) The man changed his major from art to business.

(C) The man recently moved off campus.

(D) There are two students named Robert Smith.

14. What does the woman suggest the man do in the future?

(A) See if he is related to any of the students.

(B) Apply for a job as a library assistant.

(C) Use his middle name.

(D) Use a different library. 15. What are the speakers mainly discussing?

(A) The cost of meals in the cafeteria.

(B) The size of the cafeteria.

(C) Career opportunities in cafeterias.

(D) The food served in the cafeteria.

16. What is the woman's current job in the cafeteria?

(A) Giving advice on nutrition.

(B) Cooking food for the students.

(C) Listening to complaints about service.

(D) Serving food to the students.

17. What does the man want the woman to do?

(A) Find other students who will work in the cafeteria.

(B) Collect students' opinions about meals.

(C) Ask students to try a new dish he has made.

(D) Teach students about the disadvantages of frying food.

18. What does the man suggest the cafeteria do?

(A) Stop serving hamburgers and fried chicken.

(B) Use less sauce on the food.

(C) Make some of the meals less fattening.

(D) Buy less expensive food.

19. How does the woman probably feel about the man's project?

(A) Somewhat curious.

(B) Very skeptical.

(C) Quite irritated.

(D) Not at all interested.

20. What is the man eager to tell the other student?

(A) That he will be performing in a concert.

(B) That he had a conversation with the director of a choir.

(C) That he heard a new musical composition by Barbara Johnson.

(D) That he has been translating some Latin poems for a class.

21. What can be inferred about the two students?

(A) They are members of the Latin club on campus.

(B) The work as editors.

(C) They attended the same concert.

(D) Music is their major field of study.

22. What was Barbara Johnson’s reaction to the man’s comments?

(A) She was upset.

(B) She was confused.

(C) She was amused.

(D) She was grateful.

23. What will the man probably send to Barbara Johnson?

(A) Some photographs that he took of her during the concert.

(B) A tape recording that he mad of the concert.

(C) A review of the concert that he wrote for the campus paper.

(D) The corrected text for the program of the concert. 24. What are the students mainly discussing?

(A) Places the man has visited.

(B) A paper the woman is writing for a class.

(C) School activities they enjoy.

(D) The woman's plans for the summer.

25. What does the man find surprising about the woman?

(A) She has never been to Gettysburg.

(B) She took a political science course.

(C) Her family still goes on vacation together.

(D) She's interested in the United States Civil War.

26. What is the woman unable to remember?

(A) Why her parents wanted to go to Gettysberg.

(B) Why her family's vacation plans changed ten years ago.

(C) Where her family went for a vacation ten years ago.

(D) When her family went on their last vacation.

27. What does the woman imply about Gettysburg?

(A) It's far from where she lives.

(B) Her family went there without her.

(C) She doesn't know a lot about it.

(D) She's excited about going there.

Now you will hear longer talks and discussions about academic topics. Each talk or discussions is followed by four or more questions. Choose the best answer to each question and mark the letter of the correct answer on your answer sheet. You will hear each talk or conversation only one time.

28. What does the teacher say about vegetables?

(A)They were expensive.

(B)They were grown in the castle’s garden.

(C)They were bought from nearby villages.

(D)They were kept frozen in winter.

29.According to the teacher, what was the chef’s main responsibility?

(A)Managing the kitchen workers

(B)Buying the ingredients

(C)Baking bread for everyone in the castle

(D)Presenting the food to the king and queen 30.What does the speaker main talking about?

(A)A new road in their town

(B)A new way to build roads

(C)The early history of roads

(D)The cost of building rodes

31.Why does the woman talk about animals?

(A)To explain how the first road were created

(B)To point out that long ago most people did not travel

(C)To explain a event that happened on a road

(D)To suggest that traveling on country roads can be dangerous

32.Why did people in England build ridge ways?

(A)To connect small towns to major cities

(B)To allow cars to drive

(C)To create roads that water would not wash away

(D)To create a separate road for transporting

33.What does the woman say about roads in ancient Greece?

(A)They were constructed on all of Greece’s islands.

(B)They were not as good as roads built by Romans.

(C)They were often wash away in the rain.

(D)They constructed Greece to the Roman Empire.

STOP

IF YOU FINISH BEFORE TIME IS CALLED,

YOU MAY CHECK YOUR WORK ON THIS SECTION ONLY. DO NOT TURN TO ANY OTHER SECTION IN THE TEST.

NO TEST MATERLAL ON THIS PAGE

Language Form and Meaning

Directions

In this section of the test, you will answer 37 questions found in seven different texts. Within each text are boxes that contain four possible ways to complete a sentence. Choose the word or words in each box that correctly complete each sentence. Mark the letter of the correct answer on your answer sheet.

Here are two sample questions:

1. The idea that rocks last forever and that rocks

(A) very

(B) ever

(C) quite

(D) never

2. change is not completely true. If you have ever stood next to a rushing river, you

(A) saw

(B) seen

(C) are seeing

(D) may have seen

the water hammering away at the rocks.

The correct answer to Sample 1 is (D), “never.”

The correct answer to Sample 2 is (D), “may have seen.”

Go on to the next page, and the test will begin with question number one.

1. A country’s _______ include all of its minerals, such as coal, gold, and silver.

(A) resource (B) financial (C) ability (D) list

2 .Whether two people or groups are fighting with words or weapons, we can say they are having a _______.

(A) dispute (B) war (C) combat (D) victim

3. If some lives in the _______ of your home, you would call that person a neighbor.

(A) vicinity (B) remote (C) distant (D) lonely

4. If you are always patient, we can say that you _______ lots of patience.

(A) acquire (B) erasable (C) eliminable (D) deletable

5. Roses _______ greatly in color, size, and shape.

(A) fragrant (B) vary (C) aroma (D) thorn

6. A _______ is a process that often involves a series of steps.

(A) breather (B) half-whisper (C) susurrate (D) procedure

7. If you say you have _______ time for an assignment, that means you have enough time to do it.

(A) insufficient (B) adequate (C) wanting (D. quiver

8. Anything that puts pressure on out emotions, bodies, or minds can be called _______.

(A) arrow (B) Stress (C) projectile (D) straight

9. Thelma had a _______ with her neighbors over their dogs’ getting into her garbage cans.

(A) indignant (B) approximately (C) everywhere (D) resent

10. When the Carveys didn’t pay their rent for the third month in a row, the landlord actually came to their door to _____ them.

(A) urge (B) console (C) keen (D) scold

11. In the 1800s, it must have been very difficult to _______ with people who lived far away. Today we are all lucky to have phones and good mail service.

(A) liaison (B) connect (C) beam (D) admonish

Questions 1-26

12. Snow aids farmers by keeping heat in the lower ground levels, thereby _____ from freezing.

(A) to save the seeds (B) saving the seeds (C) which saves the seeds (D) the seeds saved

13. _____ mineral content in the bones of very young children is low compared to that of adults.

(A) If the (B) That is (C) The (D) It is the

14. _____, the silvery-checked hornbill chooses a hollow tree for a nest and seals herself in until her chicks are grown.

(A) Protection for predators against

(B) Against protection predators for

(C) For protection against predators

(D) Predators against protection for

15. A floodplain is an extension of a river channel, _____ not inundated except during a flood.

(A) where is it (B) but it is (C) or is (D) in case it

16. The United States Congress made Washington, D.C., _____ in 1800.

(A) after the government center

(B) of the government center

(C) the center of government

(D) then the center of government

17. Astronomer Maria Mitchell was the first woman _____ to the American Academy of Arts and Sciences.

(A) to be elected (B) was elected

(C) which she was elected (D) for her to be elected

18. _____ of staging a play that help the audience understand its structure and meaning.

(A) Specific aspects

(B) When specific aspects

(C) Specific aspects are

(D) There are specific aspects

19. Illustrator Norman Rockwell specialized in finely drawn, richly anecdotal scenes _____.

(A) of everyday small-town lift

(B) of which everyday life in a small town

(C) were in a small town every day

(D) small-town life every day

20. _____ depends on the density of both the object and the water.

(A) An object floats whether or not

(B) Whether or not an object floats

(C) Floating an object whether or not

(D) Whether or not a floating object

21. Sturgeons are prized for their blackish roe, _____ when salted and served as an appetizer is called caviar.

(A) which (B) such (C) therefore (D) while

22. In Navajo society, not only _____ for food and for woo, but also as a means of payment or exchange.

(A) sheep were valuable (B) to value the sheep (C) the sheep's value (D) were sheep valued

23. John began to learn French last month. _______.

(A) His sister did so (B) So did his sister (C) So his sister did (D) His sister so did

24. The bridge ______ this photo was taken was built last year.

(A) which (B) how (C) who (D) where

25. Don’t put off today’s work till tomorrow. This means today’s work _____ today.

(A) must be done (B) must do (C) must to do (D) must to be done

26.--- Hello! May I speak to Mr. Smith, please?

---_________

(A) See you! (B) I agree with you. (C) Hold on, please. (D) I’d love to.

27. Catherine felt uncomfortable a speech before the public and she thought she'd ask the others for help.

(A) make (B) made (C) making (D) having made

28. Tina ________like dogs very much, but one attacked her two years ago so she doesn't like them anymore.

(A) ought to (B) used to (C) must (D) would

29. It ______at yesterday's meeting to raise salaries _______ 10% in the next two years.

(A) was decided; by (B) has decided; with (C) announced; until (D) has announced; at

30. --I don't feel like going to the party this evening.

-- . What about watching the tennis game on the computer?

(A) So do I (B) Nor I do (C) And I do (D) Neither do I

31. --Is that the time? I didn't realise it was so late. I really must be going. ---_________________

--I'm afraid so, I've got to start work early tomorrow.

(A) Didn't you have a wonderful time?

(B) Do you have to leave so early?

(C) Can we see each other again soon?

(D) Will you please stay longer?

32. --Could you tell me the times of trains to Cambridge?

--Yes, they leave on the hour.________________

--Oh, I have to wait for half an hour!

(A) If you hurry you might just get it on time.

(B) The next train will arrive in two minutes.

(C) You have no time to catch the next train.

(D) And the next one goes at 5 o'clock.

33. _____ I suggest, he always disagrees.

(A) However (B) Whatever (C) Whichever (D) Whoever

34. You should put on the notices ______ all the people may see them.

(A) where (B) in which (C) At (D) for them

35. The artist will not paint people or animals but he will paint anything ________ .

(A) that the little girl asks him

(B) the little girl asks him to

(C) for the little girl to ask him

(D) what the little girl asks him

36. October 15 th is my birthday, ________ I will never forget.

(A) when (B) that (C) what (D) which

37. He is better than _______ I last visited him.

(A) when (B) that (C) how (D) which

STOP

IF YOU FINISH BEFORE TIME IS CALLED,

YOU MAY CHECK YOUR WORK ON THIS SECTION ONLY.

DO NOT TURN TO ANY OTHER SECTION IN THE TEST.

Reading Comprehension

Directions

In this section of the test, you will read six texts and answer 30 questions. Choose the correct answer to each question and mark the letter of the correct answer on your answer sheet.

Before you start, read the sample text and the sample questions below.

Sample Text

The Golden Gate Bridge is a famous bridge in San Francisco. The bridge has a red color, but gray clouds often surround it. On clear days people come to take pictures of the bridge. The pictures show the green hills next to the bridge and the blue water under it.

Sample Question 1

What is this text mostly about?

(A)Gray clouds

(B) San Francisco

(C) A famous bridge

(D) Taking photographs

The correct answer is (C), “A famous bridge.”

Sample Question 2

What color is the Golden Gate Bridge?

(A)Red

(B) Green

(C) Blue

(D) Gray

The correct answer is (A), “Red.”

Go on to the next page, and the test will begin with question number one.

In the sixteenth century, an age of great marine and terrestrial exploration, Ferdinand Magellan led the first expedition to sail around the world. As a young Portuguese noble, he served the king of Portugal, but he became involved in the quagmire of political intrigue at court and lost the king's favor. After he was dismissed from service to the king of Portugal, he offered to serve the future Emperor Charles V of Spain.

A papal decree of 1493 had assigned all land in the New World west of 50 degrees W longitude to Spain and all the land east of that line to Portugal. Magellan offered to prove that the East Indies fell under Spanish authority. On September 20, 1519, Magellan set sail from Spain with five ships. More than a year later, one of these ships was exploring the topography of South America in search of a water route across the continent. This ship sank, but the remaining four ships searched along the southern peninsula of South America. Finally they found the passage they sought near a latitude of 50 degrees S. Magellan named this passage the Strait of All Saints, but today we know it as the Strait of Magellan.

One ship deserted while in this passage and returned to Spain, so fewer sailors were privileged to gaze at that first panorama of the Pacific Ocean. Those who remained crossed the meridian we now call the International Date Line in the early spring of 1521 after ninety-eight days on the Pacific Ocean. During those long days at sea, many of Magellan's men died of starvation and disease.

Later Magellan became involved in an insular conflict in the Philippines and was killed in a tribal battle. Only one ship and seventeen sailors under the command of the Basque navigator Elcano survived to complete the westward journey to Spain and thus prove once and for all that the world is round, with no precipice at the edge.

1.The sixteenth century was an age of great _exploration.

(A) cosmic

(B) land

(C) mental

(D) common man

(E) none of the above

2. Magellan lost the favor of the king of Portugal when he became involved in a political ___.

(A) entanglement

(B) discussion

(C) negotiation

(D) problems

(E) none of the above 3. The Pope divided New World lands between Spain and Portugal according to their location on one side or the other of an imaginary geographical line 50 degrees west of Greenwich that extends in a ___ direction.

(A) north and south

(B) crosswise

(C) easterly

(D) south east

(E) north and west

4. One of Magellan's ships explored the ___ of South America for a passage across the continent.

(A) coastline

(B) mountain range

(C) physical features

(D) islands

(E) none of the above

5. Four of the ships sought a passage along a southern __.

(A) coast

(B) inland

(C) body of land with water on three sides

(D) border

(E) answer not available

6. The passage was found near 50 degrees of ___.

(A) Greenwich

(B) The equator

(C) Spain

(D) Portugal

(E) Madrid

The longer food is kept, the more likely it is to attract insects. Even foods stored in containers often attract bugs. To solve this problem, scientists have been working with different odors in an attempt to find one strong enough to keep insects from going near food. One possibility would be to use plants with strong smells, like garlic or pine, to keep insects away. Unfortunately, however, using these smells might keep some people away too!

A more promising repellent is citronella oil, which comes from a type of lemongrass. An experiment was done using this oil with a certain insect, the red flour beetle. Scientists sprayed cardboard boxes with citronella oil and noticed that the beetles did not enter those boxes. They were much more interested in boxes that were not sprayed.

One problem with using citronella oil as a repellent, however, is that it is quite ephemeral — it simply does not last very long. After a few months it loses its smell, and bugs no longer find it unpleasant. Scientists hope to improve citronella oil so that its scent remains strong for a longer time. It will also be necessary to make sure that the oil is not harmful to people, as scientists are still not sure whether it is safe to use around food.

7. What is the passage mainly about?

(A) Oils used in cooking

(B) Ways of protecting food

(C) The behavior of a kind of beetle

(D) Smells produced by different grasses

8. The word one refers to .

(A) an odor

(B) an insect

(C) a scientist

(D) a container

9. What does the author imply about the odors of garlic and pine?

(A) They last for a long time.

(B) They are not always very strong.

(C) They can be unpleasant to people.

(D) They attract certain species of beetles.

10. What are repellents?

(A) A food source for beetles

(B) Machines used to get oil from plants

(C) Substances used to keep insects away

(D) Chemicals used to speed up plant growth

11. Which substance is NOT mentioned as being unpleasant to insects? (A) Pine

(B) Flour

(C) Garlic

(D) Citronella oil

12. What does the author say about the sprayed boxes?

(A) Beetles avoided them.

(B) They were very heavy.

(C) They did not contain much food.

(D) Many insects were trapped in them.

13.The word ephemeral is closest in meaning to .

(A) weightless

(B) short-lived

(C) overpriced

(D) not distinguishable

14. What are scientists hoping to do in the future?

(A) Breed larger beetles

(B) Produce better-tasting foods

(C) Grow lemongrass in greater quantities

(D) Make the odor of citronella oil last longer

15. The word scent is closest in meaning to .

(A) smell

(B) flavor

(C) nature

(D) standard

16. What do scientists still not know about citronella oil?

(A) What chemicals it contains

(B) Where it comes from

(C) Why beetles like it

(D) How safe it is

When another old cave is discovered in the south of France, it is not usually news. Rather, it is an ordinary event. Such discoveries are so frequent these days that hardly anybody pays heed to them. However, when the Lascaux cave complex was discovered in 1940, the world was amazed. Painted directly on its walls were hundreds of scenes showing how people lived thousands of years ago. The scenes show people hunting animals, such as bison or wild cats. Other images depict birds and, most noticeably, horses, which appear in more than 300 wall images, by far outnumbering all other animals.

Early artists drawing these animals accomplished a monumental and difficult task. They did not limit themselves to the easily accessible walls but carried their painting materials to spaces that required climbing steep walls or crawling into narrow passages in the Lascaux complex.

Unfortunately, the paintings have been exposed to the destructive action of water and temperature changes, which easily wear the images away. Because the Lascaux caves have many entrances, air movement has also damaged the images inside. Although they are not out in the open air, where natural light would have destroyed them long ago, many of the images have deteriorated and are barely recognizable. To prevent further damage, the site was closed to tourists in 1963, 23 years after it was discovered.

17. Which title best summarizes the main idea of the passage?

(A) Wild Animals in Art

(B) Hidden Prehistoric Paintings

(C) Exploring Caves Respectfully

(D) Determining the Age of French Caves

18. The words pays heed to are closest in meaning to .

(A) discovers

(B) watches

(C) notices

(D) buys

19. Based on the passage, what is probably true about the south of France?

(A) It is home to rare animals.

(B) It has a large number of caves.

(C) It is known for horse-racing events.

(D) It has attracted many famous artists.

20. According to the passage, which animals appear most often on the cave walls?

(A) Birds

(B) Bison (C) Horses

(D) Wild cats

21. The word depict is closest in meaning to .

(A) show

(B) hunt

(C) count

(D) draw

22. Why was painting inside the Lascaux complex a difficult task?

(A) It was completely dark inside.

(B) The caves were full of wild animals.

(C) Painting materials were hard to find.

(D) Many painting spaces were difficult to reach.

23. The word They refers to .

(A) walls

(B) artists

(C) animals

(D) materials

24. According to the passage, all of the following have caused damage to the paintings EXCEPT .

(A) temperature changes

(B) air movement

(C) water

(D) light

25. What does the passage say happened at the Lascaux caves in 1963 ?

(A) Visitors were prohibited from entering.

(B) A new lighting system was installed.

(C) Another part was discovered.

(D) A new entrance was created.

Well-known in many countries, tug-of-war is a sports

event with easy rules and a lot of action. On a grassy field, two teams pull on opposite ends of a rope. The team that can pull the other team to its side of the field triumphs. Many places have local tug-of-war clubs that compete against each other. An international organization sets the rules of the competition.

If one tug-of-war team weighs much more than the other team, then it is easier for the heavier team to win. To keep contests fair, all eight pullers on a team must be weighed. Only teams with similar weights compete against each other.

The thrill of tug-of-war has been known for a very long time. In fact, it is one of the world’s oldest events, going back many centuries. Tug-of-war existed in many places in ancient times, including Greece, Egypt, and Korea. At one point it was even included in the Olympic Games. It was introduced into the Olympics in 1900, just four years after the first modern Olympic Games were held in 1896 in Greece. It was a part of the Olympics until 1920, when the rope was pulled for the final time as an official Olympic event.

26. What is the best title for this passage?

(A) Games of Strength and Speed

(B) A Simple But Exciting Contest

(C) Changing the Rules of a Fun Game

(D) The Oldest Sports at the Olympic Games

27. The word triumphs is closest in meaning to .

(A) wins

(B) arrives

(C) relaxes

(D) gets tired

28. What is done before a contest begins?

(A) The rope is pulled.

(B) The field is measured.

(C) The teams are counted.

(D) The pullers are weighed

29. What does the author say about tug-of- war regarding the history of the game?

(A) It was played in ancient times.

(B) It was invented in Greece.

(C) Its rules were written down in 1900.

(D) It was a part of the first modern Olympic Games.

30. What was the last year that tug-of-war was included in the Olympics?

(A) 1896 (B) 1900

(C) 1904

(D) 1920

Dreamweaver网页设计模拟试题

一、单项选择题(每个题只有一个选项是正确的。每题3分,共60分) 1.关于网页中的换行,说法错误的是( A )。 A.可以直接在HTML代码中按下回车键换行,网页中的内容也会换行 B.可以使用
标签换行 C.可以使用标签换行 D.使用
标签换行,行与行之间没有间隔;使用标签换行,两行之间会空一行 2.下图为Dreamweaver8的新建文档页面,一般情况下,创建完全空白的静态页面应选择( A )。 A.基本页类别中的“HTML”选项 B.基本页类别中的“HTML模板”选项 C.框架集类别中的选项 D.入门页面中的选项 3.关于超链接,下列(C )属性是指定链接的目标窗口。 A. Href B. Name C. Target D. Title 4.使用Dreamweaver8将任一个单元格拆分为3行的操作正确的是( B )。 A.选择表格属性栏“拆分”对话框,设置列数为3 B.选择表格属性栏“拆分”对话框,设置行数为3 C.右键选择菜单→表格→插入行 D.直接单击“Tab”键两次

5. 如果要在网页中插入日期,最常用的操作应( D )进行设置。 A. 点击标志1 B. 点击标志2 C. 点击标志3 D. 点击标志4 6. 以下( A )属性不属于表单标记

的属性。 A. Src B. Name C. Method D. Action 7. 设置表格的行数和列数,不能采用的方法是( D )。 A. 在插入表格时设置表格的行数和列数 B. 选中整个表格,在属性面板中修改其行数和列数 C. 通过拆分、合并或删除行、列来修改行数与列数 D. 打开代码视图,在标签中修改相应属性,以修改表格的行数与列数 8. 为链接定义目标窗口时,_blank 表示的是(B )。 A. 在上一级窗口中打开 B. 在新窗口中打开 C. 在同一个帧或窗口中打开 D. 在浏览器的整个窗口中打开,忽略任何框架 9. 关于Dreamweaver 的布局模式,下列说法错误的是( B )。 A. 在布局模式下,用户可以在网页中直接画出表格与单元格 B. 在布局模式下,单元格和表格均可以用鼠标自由拖动,调整其位置 C. 利用布局模式对网页定位非常方便 D. 使用布局模式的缺点是生成的表格比较复杂,不适合大型网站使用,一般只应用于 中小型网站。 10. 关于在Dreamweaver 中插入Flash 文本,说法错误的是( C )。 A. 通过插入Flash 文本,用户可以直接创建一个Flash 文本对象的动画 B. 可以设置Flash 文本的字体、字号、文本颜色、鼠标转滚颜色等属性 C. 可以设置Flash 文本的动态效果,如淡入淡出等 D. 可以为Flash 文本设置链接

数字信号处理试题

一、 单 项选择题 1. 序列x(n)=Re(e jn π/12 )+I m (e jn π/18 ),周期为( )。 A. 18π B. 72 C. 18π D. 36 2. 设C 为Z 变换X(z)收敛域内的一条包围原点的闭曲线,F(z)=X(z)z n-1 ,用留数法求X(z)的反变换时( )。 A. 只能用F(z)在C 内的全部极点 B. 只能用F(z)在C 外的全部极点 C. 必须用收敛域内的全部极点 D. 用F(z)在C 内的全部极点或C 外的全部极点 3. 有限长序列h(n)(0≤n ≤N-1)关于τ= 2 1 -N 偶对称的条件是( )。 A. h(n)=h(N-n) B. h(n)=h(N-n-1) C. h(n)=h(-n) D. h(n)=h(N+n-1) 4. 对于x(n)= n )21(u(n)的Z 变换,( )。 A. 零点为z=21,极点为z=0 B. 零点为z=0,极点为z=21 C. 零点为z=21,极点为z=1 D. 零点为z=2 1 ,极点为z=2 5、)()(101n R n x =,)()(72n R n x =,用DFT 计算二者的线性卷积,为使计算量尽可能的少,应使DFT 的长度N 满足 。 A.16>N B.16=N C.160,Z 变换的收敛域为( )。 A. 0<|z|<∞ B. |z|>0 C. |z|<∞ D. |z|≤∞ 9.在对连续信号均匀采样时,要从离散采样值不失真恢复原信号,则采样角频率Ωs 与信号最高截止频率Ωc 应满足关系( ) A. Ωs>2Ωc B. Ωs>Ωc C. Ωs<Ωc D. |Ωs<2Ωc 10.下列系统(其中y(n)为输出序列,x(n)为输入序列)中哪个属于线性系统?( ) A.y(n)=y(n-1)x(n) B.y(n)=x(n)/x(n+1) C.y(n)=x(n)+1 D.y(n)=x(n)-x(n-1)

英语四级近三年真题作文及答案

Directions: For this part, you are allowed 30 minute to write a short essay on the topic of students selecting their lectures. You should write at least 120 words following the outline given bellow: 1. 越来越多的博物馆免费对外开放的目的是什么? 2. 也会带来一些问题 3. 你的看法? Free admission to museums 参考答案 Part I Writing Free Admission to Museums(满分版) Nowadays, an increasing number of museums are admission-free to visitors home and abroad. The hidden reason behind this is not hard to analyze as there’s a growing awareness for the authorities regarding the urgency of popularization of culture, knowledge and history with every average person in our society. Only with free access to this live ‘database’, can most people fully enjoy what museums could offer to them. However, free admission to museums might lead to some social problems as well. The most obvious problem is that it might give museums a very heavy economic burden which directly impedes the sustainable development of these organizations. As a result, our government has to work out other ways to collect funds from different channels, which might be difficult to operate or control. On the other hand, free admission attracts too many visitors, some of which might not be well-purposed and do some conscious or unconscious damage to the valuable treasures which used to be well-preserved in the museums. As a university student, I am in favor of the free-admission conduct. Yet it is proposed that some measures should be taken to solve the potential problems caused by it. For example, museums can make some regulations to guide the behavior of visitors or set some ‘closed’ days for museums for regular maintenance. Only in this way can free-admission to museums become a long-lasting phenomenon and have sustainable

工程热力学期末考试试题

一、1.若已知工质的绝对压力P=,环境压力Pa=,则测得的压差为(B)A.真空pv= B.表压力pg=.真空pv= D.表压力p g= 2.简单可压缩热力系的准平衡过程中工质压力降低,则(A) A.技术功为正 B.技术功为负 C.体积功为正 D.体积功为负 3.理想气体可逆定温过程的特点是(B)=0 =>W s>s′>s″>s′s>s″ 16.可逆绝热稳定流动过程中,气流焓的变化与压力变化的关系为(B) ====pdv 17、饱和湿空气的相对湿度(B)A.>1B.=1C.<<<1 18.湿空气的焓h为(D)湿空气的焓湿空气的焓干空气与1kg水蒸汽焓之和干空气的焓与1kg干空气中所含水蒸汽的焓之和 二、多项选择题 1.单位物量的理想气体的热容与_____有关。(ACDE)A.温度B.压力C.气体种类D.物量单位E.过程性质 2.卡诺循环是__AD___的循环。 A.理想化 B.两个定压、两个绝热过程组成 C.效率最高 D.可逆 3.水蒸汽h-s图上的定压线(AD)A.在湿蒸汽区为直线B.在过热蒸汽区为直线C.在湿蒸汽区为曲线 D.在过热蒸汽区为曲线 E.在湿蒸汽区和过热蒸汽区是斜率不同的直线 4.理想气体经绝热节流后,前后稳定截面上的__BD___相等。 5.A.压力B.温度C.比体积D.焓E.熵

《Dreamweaver网页设计》模拟题库

2016 中国开放大学 模拟题库 一、配伍题

二、单项选择题 1、下面关于网站策划的说法错误的是() A.向来总是内容决定形式的 B.信息的种类与多少会影响网站的表现力 C.做网站的第一步就是确定主题 D.对于网站策划来说最重要的还是网站的整体风格 2、下面关于素材准备的说法错误的是() A.是网站制作中的重要一环 B.在Dreamweaver中自带有准备素材的功能 C.Adobe公司的Fireworks可以和Dreamweaver很好的结合使用 D.网站徽标的设计对于制作网站来说比较重要 3、下面哪个顶层域名()可以用来标识非盈利的组织、团体。 A. .com B. .gov C. .org D. .mil 4、下面选项中关于浏览器的描述是错误的() A.浏览器主要包括IE浏览器、Firefox浏览器、苹果公司的Safari浏览器等B. Firefox紧随IE其后,并已有超越之势 C. Microsoft Office 是一款非常好用的浏览器

D.国产浏览器如360、傲游、腾讯TT等由于其采取的恰当的市场策略,整体上已压过了Firefox等在国外很流行的浏览器 5、GIF图像的优点不包括() A.它支持动画格式 B.支持透明背景 C.无损方式压缩 D.支持24位真彩色 6. 下面那些标签符合(X)HTML的语法结构() A. 国家开放大学 B. 哈利波特 C. [body] [/body] D. {book=网页设计} 7. 在Dreamweaver中插入ActiveX控件文件后,显示为() A. B. C. D. 8. 下面哪个选项不符合样式表的基本语法规则 ( ) A. a:link {color: #FF3366;font-family: "宋体";text-decoration: none;} B. a:visited {font-family: "宋体";color: #339900;text-decoration: none;} C. a:hover {color: #FF6600;font-family: "宋体";text-decoration: underline;} D. a:active (font-family: "宋体";color: #339900;text-decoration: none;) 9. 在Dreamweaver软件的主编辑窗口中,视图不包括是() A.拆分 B.级联 C. 设计 D. 代码 10. 为链接定义目标窗口时,_blank表示的是()。

数字信号处理期末试卷!

数字信号处理模拟试题一 一、单项选择题(本大题共10小题,每小题2分,共20分) 在每小题列出的四个备选项中只有一个是符合题目要求的,请将其代码填写在题后的括号内。错选、多选或未选均无分。 1.在对连续信号均匀采样时,要从离散采样值不失真恢复原信号,则采样角频率Ωs与信号最高截止频率Ωc应满足关系(A ) A.Ωs>2Ωc B.Ωs>Ωc C.Ωs<Ωc D.Ωs<2Ωc 2.下列系统(其中y(n)为输出序列,x(n)为输入序列)中哪个属于线性系统?(D) A.y(n)=y(n-1)x(n) B.y(n)=x(n)/x(n+1) C.y(n)=x(n)+1 D.y(n)=x(n)-x(n-1) 3.已知某序列Z变换的收敛域为5>|z|>3,则该序列为(D ) A.有限长序列 B.右边序列 C.左边序列 D.双边序列 4.实偶序列傅里叶变换是(A ) A.实偶序列 B.实奇序列 C.虚偶序列 D.虚奇序列 5.已知x(n)=δ(n),其N点的DFT[x(n)]=X(k),则X(N-1)=(B) A.N-1 B.1 C.0 D.-N+1 6.设两有限长序列的长度分别是M与N,欲通过计算两者的圆周卷积来得到两者的线性卷积,则圆周卷积的点数至少应取(B ) A.M+N B.M+N-1 C.M+N+1 D.2(M+N) 7.下面说法中正确的是(C) A.连续非周期信号的频谱为周期连续函数 B.连续周期信号的频谱为周期连续函数 C.离散非周期信号的频谱为周期连续函数 D.离散周期信号的频谱为周期连续函数 8.下列各种滤波器的结构中哪种不是IIR滤波器的基本结构?(C ) A.直接型 B.级联型 C.频率抽样型 D.并联型 9.下列关于FIR滤波器的说法中正确的是(C) A.FIR滤波器容易设计成线性相位特性

近三年电场高考真题及答案

电场分推试题7 1.如题3图所示为某示波管内的聚焦电场,实线和虚线分别表示电场线和等势线。两电子分别从a、b两点运动到c点,设电场力对两电子做的功分别为W a和W b,a、b两 点的电场强度大小分别为E a和E b,则 A.W a =W b,E a >E b B.W a≠W b,E a >E b C.W a=W b,E a

《热工基础》试卷A

2011-2012硅酸盐专业《热工基础》期末试题A卷 一、名词解释:(30分) 1、流体的密度—— 2、静压强—— 3、体积流量—— 4、发热量—— 5、相对湿度—— 6、黑体—— 7、干燥—— 8、完全燃烧—— 9、高温系数—— 10、干球温度—— 二、填空:(25分) 1.煤的工业分析法组成主要由__________、__________、__________、__________四种。 2.空气过剩系数是指_________________与__________________之比。 3.表示固体和液体燃料组成的基准有__________、__________、__________、__________四种。 4.传热的基本方式有__________ 、__________和__________。 5、在燃烧学中空气分为__________和________,而在干燥学中空气分为_________和________。 6、不完全燃烧分为______________和______________。 7、表示湿度的方法有三种:________、_____________、_________其中_____是为了测定方便; ______表示空气的相对干燥能力;________便于干燥计算。 三、简答题:(25分) 1、燃烧计算的内容有哪些? 2、如何对煤进行工业分析? 3、如何根据雷诺准数的大小来判断流体的流态? 4、冬天用手接触相同温度的铁块和木块时感到铁块比木块凉,这是为什么?

5、流态有几种?表现形式有何不同?如何判定? 五、计算题(20分) 1、水从三段串联管路流过,管路直径分别为:d1=100mm, d2=50mm, d3=25mm, ω3=10m/s,求ω1和ω2. 2、已知标态下CO2的密度为1.96kg/m3, O2的密度为1.43kg/m3,CO 的密度为1.25kg/m3, N2的密度为1.25kg/m3。今测得某水泥回转窑窑尾废气的体积百分比:CO2 =28.8% ,O2=1.0% ,CO =0.2%,N2=70%,求此废气标态时的密度。 3、一炉壁由耐火砖砌成,厚度δ=250mm,耐火砖内表面温度t1=1000℃, 外表面温度t2=100℃, 耐火砖平均导热系数为λ=1.28W/(m.℃)。求通过炉壁的热流量。

CEAC考试Dreamweaver模拟试题一

CEAC考试Dreamweaver模拟试题一 (1)、下面关于站点的上传和公布的讲法错误的是: 答:() A、能够通过的Dreamweaver中自带的上传功能上传站点 B、能够使用其他的上传工具上传站点 C、上传文件需要FTP服务器的支持 D、Dreamweaver中自带的上传功能支持断点续传 (3)、按下面哪个按钮能够在模板中创建重复表:答:() A、 B、 C、 D、 (5)、在Dreamweaver中,下面关于把库元素加入到网页中的讲法正确的是:答:() A、在库子面板中,选中要插入的库元素,然后单击右下角的插入按钮 B、在库子面板中选择要插入的库元素,将其拖动到网页中即可 C、在库子面板中选择要插入的库元素,按快捷键F8 D、以上讲法都错 (12)、在Dreamweaver中,下面关于拖动路径创建时刻线的讲法正确的是:答:() A、我们能够拖动层的的路径来制作动画 B、使用菜单来实现录制路径的操作时,第一要选择该层 C、形成的动画路径完全忠实于拖动的轨迹 D、在编辑状态下,时刻线的路径是不能够见的 (15)、在Dreamweaver中,下面关于层的剪裁讲法正确的是:答:() A、只能使用嵌套层来准确定位需要剪裁的坐标 B、只能使用重叠层来准确定位需要剪裁的坐标 C、能够使用嵌套层和重叠层来准确定位需要剪裁的坐标 D、以上讲法都错 (16)、在Dreamweaver中,在预览时,要使层的右方和下方显现滚动条而不论元素是否溢出,要选择溢出的下拉选项中的哪个选项:答:() A、auto B、scroll C、visible D、hidden

(32)、在Dreamveaver MX中,在插入栏的文件头属性面板中的按钮如下图所示,其表示:答:() A、输入网页关键词 B、输入网站讲明 C、网页的刷新时刻 D、网页的标题 (34)、在Dreamveaver MX中,在区中,下面的信息属性不包括的是:答:() A、题目 B、关键词 C、作者 D、背景 (37)、在Dreamweaver MX中,下面关于插入一个互动图像的操作讲法错误的是:答:() A、第一预备好两个图像,一个是正常状态,一个是鼠标移上图像后的状态 B、单击插入栏的常用子面板下的鼠标通过图像图标来插入图像 C、在弹出的鼠标通过图像面板中,单击原始图像一栏后的扫瞄按钮插入原始图像 D、遗憾的是不能够为互动图像加入超链接 (39)、通过下面高亮显示参数设置,下面哪些不能高亮度颜色显示的是:答:() A、不可编辑区颜色 B、嵌套区颜色 C、锁定编辑区颜色 D、第三方标识颜色 (42)、在HTML中,下面是超链接标签的是:答:() A、 B、… C、 D、

(43)、在HTML中,下面是段落标签的是:答:() A、… B、… C、… D、

<二>、多选题 (8)、在Dreamweaver中,在下面哪些对象中能够置入文本:答:() A、帧 B、层

数字信号处理试题及答案

数字信号处理试题及答案 一、填空题:(每空1分,共18分) 1、 数字频率ω是模拟频率Ω对采样频率s f 的归一化,其值是 连续 (连续还是离散?)。 2、 双边序列z 变换的收敛域形状为 圆环或空集 。 3、 某序列的 DFT 表达式为∑-==1 0)()(N n kn M W n x k X ,由此可以看出,该序列时域的长度为 N ,变换后数字频域上相邻两个频率样点之间的间隔是 M π 2 。 4、 线性时不变系统离散时间因果系统的系统函数为2 52) 1(8)(2 2++--=z z z z z H ,则系统的极点为 2,2 1 21-=-=z z ;系统的稳定性为 不稳定 。系统单位冲激响应)(n h 的初值 4)0(=h ;终值)(∞h 不存在 。 5、 如果序列)(n x 是一长度为64点的有限长序列)630(≤≤n ,序列)(n h 是一长度为128点 的有限长序列)1270(≤≤n ,记)()()(n h n x n y *=(线性卷积),则)(n y 为 64+128-1=191点 点的序列,如果采用基FFT 2算法以快速卷积的方式实现线性卷积,则FFT 的点数至少为 256 点。 6、 用冲激响应不变法将一模拟滤波器映射为数字滤波器时,模拟频率Ω与数字频率ω之间的 映射变换关系为T ω = Ω。用双线性变换法将一模拟滤波器映射为数字滤波器时,模拟频率Ω 与数字频率ω之间的映射变换关系为)2 tan(2ω T =Ω或)2arctan(2T Ω=ω。 7、当线性相位 FIR 数字滤波器满足偶对称条件时,其单位冲激响应)(n h 满足的条件为 )1()(n N h n h --= ,此时对应系统的频率响应)()()(ω?ω ωj j e H e H =,则其对应的相位函数 为ωω?2 1 )(-- =N 。 8、请写出三种常用低通原型模拟滤波器 巴特沃什滤波器 、 切比雪夫滤波器 、 椭圆滤波器 。 二、判断题(每题2分,共10分) 1、 模拟信号也可以与数字信号一样在计算机上进行数字信号处理,只要加一道采样的工序就可 以了。 (╳) 2、 已知某离散时间系统为)35()]([)(+==n x n x T n y ,则该系统为线性时不变系统。(╳)

近三年高考试题+答案

近三年高考完型填空和语法填空 先自己做,我已经把难点解释出来了,再看答案和总结 学习的方法因人而异 贵在坚持 不懂一定要问清楚 建议:每天背单词,先把语法书的练习做了,做过的题一定要想明白,每天做一篇完型填空或者语法填空,每周末把做过的题拿出来复习,把背过的单词再记忆一篇。 管理好时间,你在玩的时候,人家在努力,这就是差距。 还有两年。。。。有付出一定会有收获 2014 Parents feel that it is difficult to live with teenagers (it is +adj. + to do sth.做什么很。。。). Then again, teenagers have 1 feelings about their parents, saying that it is not easy living with them.(it is +adj.+doing 也可以表示做什么很。。。) According to a recent research, the most common 2 between parents and teenagers is that regarding untidiness and daily routine tasks. On the one hand, parents go mad over 3 rooms, clothes thrown on the floor and their children’s refusal to help with the 4 . On the other hand, teenagers lose their patience continually when parents blame them for(for表示因为) 5 the towel in the bathroom, not cleaning up their room or refusing to do the shopping at the supermarket. The research, conducted by St. George University,(conducted 做非谓语,和research是被动,用过去分词,后面的show 是谓语,记得一个句子只有一个谓语,其他的动词都是非谓语)shows that different parents have different 6 to these problems. However, some approaches are more7 than others(more …..than ….比什么更加。。。。). For example, those parents who yell at their children for their untidiness, but 8 clean the room for them, (定语从句,表示。。。。的父母)have fewer chances of changing their children’s 9 . On the

热工基础考试题库(带答案)

热工基础题库 一、选择题 基本概念 1.与外界只发生能量交换而无物质交换的热力系统称为。B A、开口系统 B、闭口系统 C、绝热系统 D、孤立系统 2.与外界既无能量交换又无物质交换的热力系统称为。D A、开口系统 B、闭口系统 C、绝热系统 D、孤立系统 3.开口系统与外界可以有。D A、质量交换 B、热量交换 C、功量交换 D、A+B+C 4.与外界有质量交换的热力学系统是:A A、开口系统 B、闭口系统 C、绝热系统 D、孤立系统 5.下列与外界肯定没有质量交换但可能有热量交换。B A、绝热系统 B、闭口系统 C、开口系统 D、孤立系统 6.实现热功转换的媒介物质称为。C A、系统 B、气体 C、工质 D、蒸气 7.工质应具有良好的和。A A、流动性/膨胀性 B、耐高温性/导热性 C、耐高压性/纯净 D、耐腐蚀性/不易变形 8.若闭系处于热力学平衡状态,则内部工质的处处一致。A A、压力和温度 B、压力和比容 C、比容和温度 D、压力、温度和比容 9.稳定状态是平衡状态,而平衡状态是稳定状态。B A、一定/一定 B、不一定/一定 C、一定/不一定 D、不一定/不一定 10.均匀状态是平衡状态,而平衡状态是均匀状态。C A、一定/一定 B、不一定/一定 C、一定/不一定 D、不一定/不一定 11.下列组参数都不是状态参数。C A、压力;温度;比容 B、内能;焓;熵 C、质量;流量;热量 D、膨胀功;技 术功;推动功 12.下列组参数都是状态参数。A A、焓;熵;比容 B、膨胀功;内能;压力 C、热量;比热;温度 D、技术功;动能;位能 13.下列答案是正确的。B A、10℃=43.8℉=285.15K B、10℃=50℉=283.15K C、10℃=40.2℉=285.15K D、10℃=42℉=283.15K 14.摄氏温度变化1℃与热力学绝对温度变化1K相比,有。B A、前者大于后者 B、两者相等 C、后者大于前者 D、不一定 15.摄氏温度变化1℃与华氏温度变化1℉相比,有。B A、前者大于后者 B、两者相等 C、后者大于前者 D、不一定 16.若大气压力为100KPa,真空度为60KPa,则绝对压力为。D A、160KPa B、100KPa C、60KPa D、40KPa 17.若大气压力为100KPa,表压力为60KPa,则绝对压力为。A A、160KPa B、100KPa C、60KPa D、40Kpa 18.在工程热力学计算中使用的压力是。A A、绝对压力 B、表压力 C、真空压力 D、大气压力 19.若大气压力为0.1Mpa,容器内的压力比大气压力低0.004Mpa,则容器的B。 A、表压力为0.096Mpa B、绝对压力为0.096Mpa C、真空度为0.104Mpa D、表压力为0.104Mpa

DreamWeaver 认证模拟试题1(已看)

DreamWeaver 认证模拟试题1 发布日期:2007-12-1 23:35:35 作者:admin 来源:本站浏览:1368 一、单选题:请从四个选项里找出最正确的答案. 1. DreamWeaver 的View 菜单中,载入追踪图象的选项是? A. Tracing Images>show B. Tracing Images>adjust posistion C. Tracing Images>reset posistion D. Tracing Images>load 解析: Tracing Images>load 命令用来载入追踪图象,载入追踪图象之后可用Tracing Images>show 控制追踪图象的隐藏或显示,Tracing Images>adjust posistion 命令用来调整追踪图象在页面中的位置,Tracing Images>reset posistion 命令可把追踪图象的顶点坐标复位到0,0 答案:D 2. Dreamweaver 打开模板选项板的快捷操作是? A. F11 B. Ctrl+F10 C. DW4 中没有设置 D. F4

答案:C 3. Dreamweaver 打开样式面板的快捷操作是? A. Shift + F11 B. F8 C. F9 D. F10 答案:A 4. DreamWeaver 是利用什么标记构建的分层? A.〈dir〉 B.〈div〉 C.〈dis〉 D.〈dif〉 解析: 在DreamWeaver 中层的标记有四种可选,DIV,SPAV,ILAYER, LAYER 答案:B 5. 一个有3 个框架的Web 页实际上有几个独立的HTML 文件? A. 2 B. 3

数字信号处理期末试题及答案汇总

数字信号处理期末试题及答案汇总

数字信号处理卷一 一、填空题(每空1分, 共10分) 1.序列()sin(3/5)x n n π=的周期为 。 2.线性时不变系统的性质有 律、 律、 律。 3.对4 ()()x n R n =的Z 变换为 ,其收敛域为 。 4.抽样序列的Z 变换与离散傅里叶变换DFT 的关系为 。 5.序列x(n)=(1,-2,0,3;n=0,1,2,3), 圆周左移2位得到的序列为 。 6.设LTI 系统输入为x(n) ,系统单位序列响应为h(n),则系统零状态输出y(n)= 。 7.因果序列x(n),在Z →∞时,X(Z)= 。 二、单项选择题(每题2分, 共20分) 1.δ(n)的Z 变换是 ( )A.1 B.δ(ω) C.2πδ(ω) D.2π 2.序列x 1(n )的长度为4,序列x 2(n )的长度为3,则它们线性卷积的长度是 ( ) A. 3 B. 4 C. 6 D. 7 3.LTI 系统,输入x (n )时,输出y (n );输入 为3x (n-2),输出为 ( ) A. y (n-2) B.3y (n-2) C.3y (n ) D.y (n ) 4.下面描述中最适合离散傅立叶变换DFT 的是 ( ) A.时域为离散序列,频域为连续信号 B.时域为离散周期序列,频域也为离散周期序列

C.时域为离散无限长序列,频域为连续周期信号 D.时域为离散有限长序列,频域也为离散有限长序列 5.若一模拟信号为带限,且对其抽样满足奈奎斯特条件,理想条件下将抽样信号通过即可完全不失真恢复原信号()A.理想低通滤波器 B.理想高通滤波器 C.理想带通滤波器 D.理想带阻滤波器 6.下列哪一个系统是因果系统()A.y(n)=x (n+2) B. y(n)= cos(n+1)x (n) C. y(n)=x (2n) D.y(n)=x (- n) 7.一个线性时不变离散系统稳定的充要条件是其系统函数的收敛域包括()A. 实轴 B.原点C.单位圆 D.虚轴 8.已知序列Z变换的收敛域为|z|>2,则该序列为()A.有限长序列 B.无限长序列C.反因果序列 D.因果序列 9.若序列的长度为M,要能够由频域抽样信号X(k)恢复原序列,而不发生时域混叠现象,则频域抽样点数N需满足的条件是( ) A.N≥M B.N≤M C.N≤2M D.N≥2M 10.设因果稳定的LTI系统的单位抽样响应h(n),在n<0时,h(n)= ( )

工程热力学期末试题及答案

工程热力学期末试卷 建筑环境与设备工程专业适用 (闭卷,150分钟) 班级 姓名 学号 成绩 一、简答题(每小题5分,共40分) 1. 什么是热力过程?可逆过程的主要特征是什么? 答:热力系统从一个平衡态到另一个平衡态,称为热力过程。可逆过程的主要特征是驱动过程进行的势差无限小,即准静过程,且无耗散。 2. 温度为500°C 的热源向热机工质放出500 kJ 的热量,设环境温度为30°C ,试问这部分热量的火用(yong )值(最大可用能)为多少? 答: =??? ? ?++- ?=15.27350015.273301500,q x E 303.95kJ 3. 两个不同温度(T 1,T 2)的恒温热源间工作的可逆热机,从高温热源T 1吸收热量Q 1向低温热源T 2放出热量Q 2,证明:由高温热源、低温热源、热机和功源四个子系统构成的孤立系统熵增 。假设功源的熵变△S W =0。 证明:四个子系统构成的孤立系统熵增为 (1分) 对热机循环子系统: 1分 1分 根据卡诺定理及推论: 1分 4. 刚性绝热容器中间用隔板分为两部分,A 中存有高压空气,B 中保持真空,如右图所示。若将隔板抽去,试分析容器中空气的状态参数(T 、P 、u 、s 、v )如变化,并简述为什么。 答:u 、T 不变,P 减小,v 增大,s 增大。 自由膨胀 12iso T T R S S S S S ?=?+?+?+?W 1212 00ISO Q Q S T T -?= +++R 0S ?= iso S ?=

5. 试由开口系能量程一般表达式出发,证明绝热节流过程中,节流前后工质的焓值不变。(绝热节流过程可看作稳态稳流过程,宏观动能和重力位能的变化可忽略不计) 答:开口系一般能量程表达式为 绝热节流过程是稳态稳流过程,因此有如下简化条件 , 则上式可以简化为: 根据质量守恒,有 代入能量程,有 6. 什么是理想混合气体中某组元的分压力?试按分压力给出第i 组元的状态程。 答:在混合气体的温度之下,当i 组元单独占有整个混合气体的容积(中容积)时对容器壁面所形成的压力,称为该组元的分压力;若表为P i ,则该组元的状态程可写成:P i V = m i R i T 。 7. 高、低温热源的温差愈大,卡诺制冷机的制冷系数是否就愈大,愈有利?试证明你的结论。 答:否,温差愈大,卡诺制冷机的制冷系数愈小,耗功越大。(2分) 证明:T T w q T T T R ?==-= 2 2212ε,当 2q 不变,T ?↑时,↑w 、↓R ε。即在同样2q 下(说明 得到的收益相同),温差愈大,需耗费更多的外界有用功量,制冷系数下降。(3分) 8. 一个控制质量由初始状态A 分别经可逆与不可逆等温吸热过程到达状态B ,若两过程中热源温度均为 r T 。试证明系统在可逆过程中吸收的热量多,对外做出的膨胀功也大。

DreamWeaver 考试模拟试题一

一、单选题:请从四个选项里找出最正确的答案. 1. DreamWeaver 的View 菜单中,载入追踪图象的选项是? A. Tracing Images>show B. Tracing Images>adjust posistion C. Tracing Images>reset posistion D. Tracing Images>load 解析: Tracing Images>load 命令用来载入追踪图象,载入追踪图象之后可用Tracing Images>show 控制追踪图象的隐藏或显示,Tracing Images>adjust posistion 命令用来调整追踪图象在页面中的位置,Tracing Images>reset posistion 命令可把追踪图象的顶点坐标复位到0,0 答案:D 2. Dreamweaver 打开模板选项板的快捷操作是? A. F11 B. Ctrl+F10 C. DW4 中没有设置 D. F4 答案:C 3. Dreamweaver 打开样式面板的快捷操作是? A. Shift + F11 B. F8 C. F9 D. F10 答案:A 4. DreamWeaver 是利用什么标记构建的分层? A.〈dir〉

C.〈dis〉 D.〈dif〉 解析: 在DreamWeaver 中层的标记有四种可选,DIV,SPAV,ILAYER, LAYER 答案:B 5. 一个有3 个框架的Web 页实际上有几个独立的HTML 文件? A. 2 B. 3 C. 4 D. 5 解析:一个有3个框架的Web页中每个框架包含一个独立的HTML文件,共 3 个,另外,在加上一个框架结构页,共 4 个HTML 文件 答案:C 6. CGI 脚本语言环境变量SERVER_PORT 的意义是下列哪一项? A. 在PATH_INFO 中系统规定的路径信息 B. 附加的路径信息, 由浏览器通过GET 方法发出 C. 指向这个CGI 脚本的路径 D. 服务器运行的TCP 口,通常Web 服务器是80. 答案:D 7. DreamWeaver 的Modify 菜单中,将单元格分离为行或列选哪项? A. Hyperlink→Taget Frame→Set B. Table→Select Table C. Table→Merge Cells D. Table→Split Cell

2017数字信号处理模拟题a答案

1. 两个有限长序列x1(n),0≤n ≤33和x2(n),0≤n ≤36,做线性卷积后结果的长度是 70 , 若对这两个序列做64点循环卷积,则圆周卷积结果中n= 6 至 64 为线性卷积结果。 2. 一线性时不变系统,输入为 x (n )时,输出为y (n ) ;则输入为2x (n )时,输出为 ; 输入为x (n-3)时,输出为 3. 若正弦序列x(n)=sin(30n π/120)是周期的,则周期是N= 8 4. 如果一台计算机的速度为平均每次复乘5μS ,每次复加0.5μS ,用它来计算512 点的DFT[x(n)],问直接计算需要多少时间,用FFT 运算需要多少时间。 1、 直接计算 复乘所需时间 62621510510512 1.31072T N s --=??=??= 复加所需时间()6610.51010.5105125110.130816T N N s --=???-=???= 所以12 1.441536T T T s =+= 2、用FFT 计算 复乘所需时间 66122512510log 510log 5120.0115222 N T N s --=?? =??= 复加所需时间662220.510log 0.510512log 5120.002304T N N s --=??=??= 所以120.013824T T T s =+=

6.设系统差分方程 y(n)=ay(n-1)+x(n) 其中x(n)为输入,y(n)为输出。当边界条件选为y(-1)=0时,是判断系统是否线性的、移不变的

7.用级联型结构实现以下系统函数,试问一共能构成几种级联型网络,并画出其中一种的信号流图。 ()() ()() 22 41 1.41()0.50.90.8Z Z Z H z Z Z Z +-+= -++

相关文档
最新文档