初中英语状语从句教案

初中英语状语从句教案

【篇一：英语中考复习教案专题十三状语从句】

学习过程

一、复习预习

1、在句中作状语用的从句叫状语从句，状语从句可修饰谓语，非谓语动词、定语、状语或整个句子。状语从句可以在句首，也可在句中或句末。

2、引导状语从句的一般为连词，也可有词组。

3、状语从句按用途可有时间、原因、条件、让步、目的、结果、方式、地点、比较等九种。

4、状语从句中的将来时，一般不用将来时。（一般将来时用一般现在时、将来完成时用现在完成时、过去将来时用一般过去时、过去

将来完成时用过去完成时表示。)

二、知识讲解

考点1——时间状语从句

常用引导词: when，as，while，as，soon as，while，before，after，since，till，until 特殊引导词:the minute, the moment, the day, immediately,no sooner ?than, hardly ?when, scarcely ? when

1) when, while, as的区别：

①三者均可表示“当??的时候”, 如果主句表示的是短暂的动作, 而从句表示的是一段时间, 三者可通用。

② as和when都可与终止性动词连用, while 只能与延续性动词连用。如：

it was snowing ____ we got to the airport．当我们到达机场时, 天正下着雪。（不能用 while）

③as强调主句与从句表示的动作同时发生; while强调主句表示的动作持续于while所指的整个时间内; when可指主、从句所述动作同时或先后发生。如:

he sang as he went along. 他边走边唱.

please write____ i read. 我读的时候, 请写下来。

____ he reached home, he had a little rest. 回到家后, 他休息了一会儿。

whenever we met with difficulties, they came to help us.

i got in touch with him immediately i received his letter.

my sister came directly she got my message.

every time i catch a cold, i have pain in my back.

如果把no sooner, hardly, scarcely, barely置于句首，它所连带的这部分要倒装，如： no sooner had she heard the news than she fainted.

(she had no sooner heard the news than she fainted.)

考点2——条件状语从句

常用引导词: if,unless，(if not)

特殊引导词:as/so long as，on condition that

① we’ll start our project ___ the president agrees.

② you will certainly succeed ____ ___ ___ you keep on trying.要点: 引导条件状语从句的连词有if(如果)、unless(除非)等, unless 在意义上相当于if?．not。条件状语从句也像时间状语从句一样，如果主句用将来时, 从句要用现在时代替将来时。如：

you will fail ____ you study hard．

(＝you will fail if you dont study hard．)除非你努力学习, 否则你会失败。注意：有时可以把祈使句作为条件从句，祈使句后面要搭配and，如：

come tomorrow, and i will tell you./persevere and you will succeed.

give him an inch and he’ll take a mile. (= if you give him an inch, he’ll take a mile. )

但：当表示否定的条件时，可用连词or 或otherwise，如：

make up your mind, or you’ll miss the chance.

start at once, or / otherwise you’ll miss the train.

(= if you don’t start at once, ?)

(= unless you start at once, you’ll miss the train.)

考点3——原因状语从句

(1)常用引导词: because, since, as , now that

(2)because, since, as, for 用法比较：

一）.because: 语气最强，回答why引导的疑问句，该从句一般位于主句后，所表示的是直接理由，因果关系不能同so连用。

why are you late?because there is a traffic jam.

—why cant i go? 为什么我不能去?

— ____ youre too young. 因为你年纪太小了。

二）.since: “既然?..” 表对方已知的事实或理由，从句常放在句首。since比as正式。since you have got enough money with you now, you can come and buy it next time.

三）. as: “由于?.” 语气较弱较口语化，表明显的原因或已知的事实，从句常放在句首。as he had been ready for the worst, he was

not disappointed at the result. ____you are not feeling well，youd better stay at home．

既然你不太舒服，还是留在家里的好

四）.for是一个等立连词，连接的是两个并列的分句，其他三个引

导的是状语从句；for不能放在句首。

it must have rained last night, for the ground is wet.

考点4——目的状语从句

常用引导词:so that，in order that

引导目的状语从句时，从句中常有can, could, may, might, would

① the boss asked the secretary to hurry up with the letters

__________ he could sign them.

② the teacher raised his voice _______________ the students

in the back could hear more clearly.

考点5——结果状语从句

常用引导词: so?that，such?that

1. so?that和such?that引导的结果状语从句,意为“如此..以至于”,用来补充说明主句动作发生所带来的结果

the boy is so young that he cannot go to school

it is such nice weather that i would like to go to the beach

2.so?that中so是副词，用来修饰形容词或副词：so + 形容词/副

词/分词 + that引导结果状语从句

he studied so hard that he made great progress

such?that中 such是限定词，只能修饰名词和名词词组，such + (形容词) + 名词 + that引导结果状语从句

mike is such an honest man that we all believe

3.(1)主+谓+so+adj./adv+that 从句.

(2)主+谓+so+adj+a(n)+单数名词+that从句 .

主+谓+such+a(n)+adj.+单数名词+that从句 .

it’s such a fine day that we all want to go outing.

= it’s so fine a day that we all want to go outing.

（3）主+谓+so+many/much/few/little(少)+名词+that从句 eg.

if修饰名词的形容词为many,few,much,little时，前面则用so，例如：

比较：so many / few flowers → such nice flowers

so much / little money → such rapid progress

so many people → such a lot of people

（5）主+谓+such+adj.+复数名词+that从句 eg.

（6）主+谓+such+adj.+不可数名词+that从句 eg.

he got up ___ early that he caught the first bus.他起得很早，赶上了第一班车

it’s ____ a good chance that we must not miss it. 机会很难得，我们一定不能错过 he spoke ___ fast that i couldnt follow him．他讲得太快，我跟不上。

he told us ____funny stories that we all laughed．他给我们讲了那么多有趣的故事，我们全都哈哈大笑。

考点6——让步状语从句

（1）常用引导词:though，although，even if/even though

特殊引导词：no matterwho/ what/ when / where/ which / how ( whoever, whatever, whenever, wherever, whichever, however)① _____ it’s hard work, i enjoy it．

尽管这工作很辛苦, 我还是很喜欢。

② ____ _____ how hard the work was，he never gave it up．不管工作多么艰难, 他都从不放弃。

（2）whoever, whatever, whichever还可引导名词从句。而no matter who/ what/ which 只能引导让步状语从句

he didn’t want to be disturbed, no matter who wanted to see him.

= he didn’t want to be disturbed, whoever wanted to see him. i’ll give the books to whoever needs them.

考点7——地点状语从句

常用引导词:where

特殊引导词:wherever(no matter where), anywhere, everywhere

① air will be heavily polluted where there are factories.

② wherever you go, you should work hard.

where there is a will, there is a way.

________________________.

wherever you go, i go too．

无论你去哪里, 我都去。

where i live there are plenty of trees. 我住的地方树很多。

wherever i am i will be thinking of you. 不管我在哪里我都会想到你。

四、课堂运用

1. —mike wants to know if ___ a picnic tomorrow．

—yes. but if it ___, well visit the museum instead

a. you have; will rain

b. you will have; will rain

c. you will have; rains

d. will you have; rains

2. —do you know when he ___ back tomorrow？

—sorry, i dont. when he ___ back, ill tell you

a. comes; comes

b. comes; will come

c. will come; comes

d. will come; will come

3. it _____ ten years since they ____ to france.

a. as; covered

b. was; have moved

c. is; have moved

d. is; moved

4. he ____ wait until the rain ____．

a. wont; will stop

b. wont; stop

c. will; stops

d. will; will stop

5. he will go to the great wall if it ___ tomorrow．

a. wont rain

b. doesnt rain

c. dont rain

d. isnt raining

6. ___ you eat old food, you may be ill.

a. before

b. why

c. if

d. which

7.jack runs as ___ as tom．

a. fast

b. faster

c. fastest

d. much

8. 30，000dollars is a large amount of money, but its ____ than we need．

a. for more

b. very much

c. far less

d. very little

9. miss gao asked a question, but it was ___ that nobody could answer it．

【篇二：状语从句教案】

状语从句

联系链：

1。引导词的角度

（1）可以同时用于名词性从句和状语从句的引导词：when , whatever , that , where

(2)可以同时用于形容词性从句和状语从句的引导词：as , that , where , when

2. 功能的角度

（1）状语从句具有副词的功能

（2）定语从句具有形容词的功能

（3）名词性从句具有名词的功能

3. 从句所作成分的角度

（1）名词性从句充当：主语，宾语，表语，同位语（2）形容词性从句充当：定语

（3）副词性从句充当：状语

4. 句子结构的角度

(1 ) 状语从句和名词性从句成分完整

(2 )定语从句成分不完整

5。语序角度

状语从句倒装特殊句式

6。连词角度

主从句的逻辑关系两个句子的关系并列句

知识链

1。状语从句时间状语从句

地点状语从句

原因状语从句

目的状语从句

条件状语从句

结果状语从句

让步状语从句

比较状语从句

方式状语从句

2。功能角度

在整个主从句中作状语

3。从句关系角度

主从句中的主谓不一致

4。主从句位置角度

可前可后

5。语境角度

主从句逻辑关系选择连词部分连词引起的倒装

6。时态的角度

时间状语从句和条件状语从句中，主句用将来时，从句一般用现在

时

模型链

状语从句

定义：在复合句中由从句表示的状语称作状语从句，它可以用来修

饰谓语（包括非谓语动词）、定语或状

语，或是整个句子。状语从句通常由一个连词引起，也可以由一个

起连词作用的词组引起，有时甚至不需要连词直接和主句连接起来。状语从句一般分为九大类（见下表）

1．时间状语从句：

在时间状语从句中，要注意时态一致，一般情况下主句是将来时的

时候，从句要用一般现在时。可以引导时间状语从句的连词很多，

根据意义和主从句之间的时间关系，又可分类如下：

(1) 表示同时性，即主从句的谓语动作同时发生或几乎同时发生。其

连词有：when （当……的时候）, while

（当……的时候）, as（当……的时候）, as soon as（一……就……）, once（一旦……）等。如： strike while the iron is hot.

趁热打铁。

while i am washing the floor, you can be cleaning the windows.（while含有对比的意思）

我洗地板的时候，你可以擦窗户。

as / when i came home, i met an old schoolmate of mine.我回

家的时候遇到了我的一位老同学。

i’ll ring you up as soon as i get an answer from him.我一有他的

答复就给你打电话。

once you see him, you will never forget him. 你一旦见过他，就

不会忘了他的。

(2) 表示先时或后时，即主句的谓语动作发生在从句之前或之后，主

要连词有：after（在……之后）, before

（在……之前）, when(=after)等。如：

after / when the children had gone to bed, she began to

prepare her lessons.（从句的动作发生在主句的动作之前，所以从

句用了过去完成时）孩子睡觉了以后她开始备课。

he had learned english for three years before he went to london.（主句的动作发生在从句的动作之前，所以主句用了过去完

成时）他去伦敦之前已学了三年英语。

it was not long before i forgot it all.(it is / was / will

be …before…是常用句型)

he ran off before i could stop him.（主句和从句的动作几乎同时

发生，时态一致）

我还没来得及阻止他他就跑掉了。(注意before在汉语中的译义)

(3) 表示习惯性、经常性，即从句描述的不是一次性动作，而是经常

发生的习惯性动作。主要连词有every

time（每次）, each time（每次）, whenever（每当）等。例如：

whenever we met with difficulties, they came to help us.每当我

们遇上困难的时候，他们就来帮我们。 each time he came to town he would visit our school.他每次进城，总要来看看我们的学校。

every time i went to his house, he was out.我每次去他家，他都

出去了。

（4）表示持续性或瞬间性，主要连词有：since（自从）, ever since（自从）, until（直到……才/为止）, till

（直到……才/为止）等。如： it is just a week since we arrived here.（it is /was… since…是常用句型）我们到这儿刚刚一星期。(主句的动作或状态持续时间较短，不能用ever since)

you have been reading to me ever since james went out.（ever 放在since之前是用来表示说话者强调

主句动作或状态持续时间长）自从james走后你一直在给我朗读。

the big clock which used to strike the hours day and night was damaged during the war and has been silent ever since.( ever since可以放在句末， since则不能)

这只一向日夜不停打点报时的大钟在战争中损坏了，从此就一直不

响了。

my uncle went to tibet in 1951. he has been living there ever since.我叔叔于1951年去了西藏，从那以后他一直生活在那里。

things went well until / till one night an accident happened.事

情一切正常，直到有一天晚上发生了意外。 i knew nothing about

it until / till he told me.(但until he told me, i knew nothing

about it. “till”不位于句首)他告诉我了我才知道。

2．地点状语从句

地点状语从句是由where（在……的地方）, wherever（无论哪里）引导的：

wuhan lies where the yangtze and the han river meet.武汉位于长江和汉水汇合处。

where there is a will, there is a way.有志者，事竟成。

you’d better make a mark where you have any questions.(这里where引导的从句不是定语从句)哪有问题，你最好在哪做个记号。 he would keep in touch with us wherever he was .他无论在什么地方，总是与我们保持联系。

3．原因状语从句

表示原因的状语从句可以由as（由于）, because(因为), since（既然）, now (that) （既然）, considering that（顾及到）, seeing that（由于）等连词引导：

i do it because i like it.因为我喜欢我才干。(because不能与 so 连用)

he couldn’t have seen me, because i was not there.他不可能见过我，因为当时我不在那儿。

seeing (that) quite a few people were absent, we decided to put the meeting off.由于好些人都没到会，我们决定延期开会。now that/since you are all here, let’s try and reach a decision.既然大家都来了，咱们就设法做出一个决定吧。

as she was ill, she didn’t come to the party.由于病了，她没来参加晚会。

considering that they are just beginners, they are doing quite

a good job.考虑到他们才刚刚学做，他们干得算很不错的了。

4. 目的状语从句

引导目的状语从句的主要连词有:that, so that（以便）, in order that（为了）, for fear that（以便）, in case（万

一）等，从句中常常使用一些情态动词，如：can, could, may, might, should等。如：

let’s take t he front seats (so) that we may see more clearly. 我们坐前排吧，这样我们看得更清楚些。

school was closed early in order that the children might go home ahead of the storm.早点儿放学是为了让孩子们在暴风雨到来之前回家。

he took the name down for fear that he should forget it.他把名字写下省得忘了。（该从句中一般用情态动词should+动词原形，或省略should）

better take more clothes in case the weather is cold.最好多带

些衣服以防天气会冷。

引导结果状语从句的连词有：that, so that（从句中不带情态动词）, so…that(如此……以致..), such…that(如此……以致……)等。

what has happened that you all look so excited? 发生了什么事，使你们都显得如此兴奋？

he didn’t plan his time well, so that/so he didn’t finish the work in time.他没把时间计划好，结果没按时完成这项工作。

we left in such a hurry that we forgot to lock the door. 我们走得匆忙，把门都忘了锁了。（such是形容词，后接名词）

the village is so small that it cannot be shown in the map.这村

子太小，所以这地图上没有。（so是副词，后接形容词或副词）

jenny is such a clever girl that all the teachers like her very much = jenny is so clever a girl that….jenny是如此聪明的女孩，以至老师们都非常喜欢她。

但是，当名词前有many, much, few, little(少)修饰时，要用so,不

能用such。例如：

i have had so many falls that i am black and blue all over.我摔

了许多跤，以至于浑身青一块，紫一块。 he has so few friends

that he often feels lonely.他朋友很少，所以经常感到孤独。

i had so little money then that i couldn’t afford a little present.

我当时囊肿羞涩，连一份小小礼物都买不起。

6．条件状语从句

表示条件的状语从句可以由if（如果）, unless（除非）, in case

（万一）, so /as long as（只要）, as/ so far as（就……而言）,

on condition that（条件是……）, suppose（假设）, supposing （假设）（仅用在问句中）等词或词组引导。一般情况下当主句是

将来时的时候，从句要用一般现在时。

as/so long as we don’t lose heart, we’ll find a way to overcome the difficulty.只要我们不灰心，我们就能找到克服困难的方法。

send us a message in case you have any difficulty.万一你有什

么困难，请给我们一个信儿。

if you leave at 6 o’clock tomorrow morning, you’d better get to bed now.如果你明早6点钟走，你最好现在就上床。

we’ll let you use the room on condition that you keep it clean and tidy.只要你能保持整洁，我们可以让你使用这个房间。

as/so far as i know, he is an expert on dna.据我所知，他是一个dna专家。

he’ll accept the job unless the salary is too low/ if the salary is not too low.他会接受这项工作的，除非薪水太少/如果薪水不太少的话。

suppose/supposing we can’t get enough food, what shall we do?假设我们弄不到足够的食物，那我们怎么办？

7．方式状语从句

方式状语从句常由as（与……一样）, as if（仿佛）, as though

（仿佛）等词引导：

do in rome as the romans do.入乡随俗。

leave things as they are.让一切顺其自然。

she stood at the door as if (=as though) she were waiting for someone.她站在门口，仿佛在等人似的。（由as if或 as though

引导的从句中可用虚拟语气）

比较状语从句常由than（比）, as（与……一样）等词引导：

it rains more often in shanghai than in beijing.上海下的雨比北

京的多。

our country is as big as the whole of europe.我们的国家同整个

欧洲一样大。

the result was not as/so good as i had expected.结果不如我预

料的那么好。

the busier he is, the happier he feels.（常见句型）他越忙越开心。 9．让步状语从句

让步状语从句由although（尽管）, though（尽管）, however

（无论怎样）, whatever（无论什么）, whoever（无论谁）, whomever（无论谁）, whichever（无论哪个）, whenever（无论

何时）, wherever（无论哪里）, whether（是否）, no matter (who, what, where, when, etc) （无论……）, even if（即使）, even though（即使）等词引导。如：

we won’t be discouraged even if(=even though) we fail ten times.我们就是失败十次也不泄气。

it was an exciting game, though / although no goals were scored.那是一场精彩的球赛，尽管一个球都没进。(though, although不能与 but连用)

whether you believe it or not, it’s true.不管你信不信，这是真的。

however (=no matter how) expensive it may be, i’ll take it.无论

它有多贵，我也要买下它。

don’t let them in, whoever(=no matter who) they are.不管他们

是谁，别让他们进来。

no matter what i say or how i say it, he always thinks i’m wrong.无论我说什么或怎么说，他总认为是我错。连词as也可以

引导让步状语从句，但从句中要用特殊语序。如：

young as he is, he knows a lot=though he is young 或young though he is, he….

他虽然年轻，但懂得很多。(though 也有这种用法，可以替换as,但although没有这种用法)

though还可以用作副词，放在句末。如：

it was hard work;; i enjoyed it, though=it was hard work, but i enjoyed it.那工作很苦，但是我喜欢干。

【篇三：状语从句——原因和目的状语从句教案】

一、复习预习

状语从句指句子用作状语时，起副词作用的句子。它可以修饰谓语、非谓语动词、定语、状语或整个句子。根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式和比较等从句。状语从

句一般由连词(从属连词)引导，也可以由词组引起。从句位于句首或

句中时通常用逗号与主句隔开，位于句尾时可以不用逗号隔开。

二、知识讲解

知识点：

【考查点1】

原因状语从句是用来说明引起主句这个结果的原因的从句，在初中

阶段引导原因状语从句的从属连词主要的有because, as, since,for，seeing (that), now (that), considering (that)，in that等：

the woolly shrank because it was washed badly. 毛衣因洗得不

得法而缩水。

i can’t get to sleep becaus e of the noise outside. 由于外面声音

嘈杂我睡不着。

since [as] we’ve no money, we can’t buy it. 由于我们没钱，我们

无法购买它。

seeing that it’s raining, we’d better stay indoors. 既然外边在下雨，我们最好待在室内。

now that you are here, you’d better stay. 你既然来了，最好还是留下吧(既来之，则安之)。

【注】除以上提到的大家比较熟悉的引导原因状语从句的从属连词外，when有时也可引导原因状语从句(when表示“既然”)

i won’t tell you when you won’t listen. 既然你不想听，我就不告诉你了。

原因状语从句应注意的问题

1、because , since , as , for,辨析

1）because语势最强，用来说明人所不知的原因，回答why提出的问题。当原因是显而易见的或已为人们所知，就用as或 since。

i didn’t go, because i was afraid.

since /as the weather is so bad, we have to delay our journey. 2）由because引导的从句如果放在句末，且前面有逗号，则可以用for来代替。但如果不是说明直接原因，而是多种情况加以推断，就只能用for。例：

he is absent today, because / for he is ill.he must be ill, for he is absent today.

3） as和for的区别：通常情况下，as引导的从句在主句前，for

引导的从句在主句后。例：as the weather is cold, i stay at home.（同义句）i stay at home, for the weather is cold.

2、because习惯上不与so连用

汉语习惯上说“因为?所以?”，但英语习惯上却不能将 so与because 连用：

正：because it was raining, we stayed at home. / it was raining, so we stayed at home. 误：because it was raining, so we stayed at home. 因为下雨，所以我们呆在家里。

3、because 从句与 because of短语的转换

because引导的原因状语从句有时可与because of 短语转换，because of后加的原因可以为好或坏，但最正规的还是because。he can’t come because he is ill. / he can’t come because of his illness. 他因病不能来。 i said nothing about it because his wife was there. / i said nothing about it because of his wife’s being there. 因为他妻子在那儿，我对此事只字未提。

常见考法

对于原因状语从句的考查，多以单选和完形填空的形式，从连词的

意义角度让大家选择连词。

典型例题：he found it increasingly difficult to read, ____ his eyesight was beginning to fail.

a. and

b. for

c. but

d. or

解析：“his eyesight was beginning to fail”是“he found it increasingly difficult to read”的原因，因此本题应选用可以表示

原因的连词for引导原因状语从句。

答案： b

误区提醒

除了because , since , as , for这四个词的辨析外，对于because

从句与 because of短语的区分也是难点之一。because引导的原因状语从句有时可与because of 短语转换，because of后跟的是短语，because后跟的是句子。

典型例题：he didnt go to work the heavy rain.

a .becauseb.because of c.so d.since

答案：b

【考查点2】

目的状语从句用来说明主句中谓语动词发生的目的的从句叫做目的

状语从句。表示目的状语的从句可以由that(以便)，so that(以便)，in order that(为了;以便)，lest(免得;唯恐)， for fear that(生怕;以免)等词引导;目的状语从句的谓语常含有may, might, can, could, should, would等情态动词。

例如：you must speak louder so that /in order that you can be heard by all.

he wrote the name down for fear that(lest) he should forget it.

better take more clothes in case the weather is cold.

学习目的状语从句应注意以下两点：

(1)目的状语从句中常含有can,could,may,might,should等情态动词。例如：

i got up early so that i could catch the first bus. 我起得很早，目的是为了赶上头班公共汽车。

(2)在口语中so可以引导目的状语从句。例如：

well sit nearer the front so we can hear better. 我们坐的靠前一点，因此，我们听得清楚一点。

1、in order that与in order to的区别：

in order that+从句in order to+动词原形( in order to后面加的那

个不叫目的状语从句，叫目的状语) 例如：

he got up early in order to take the first bus.

= he got up early

in order that he could take the first bus.(他起床很早是为了赶上

第一班公共汽车)

目的状语从句的一个特点：由于目的都是未来的行为，所以从句中

一般用表示未来可能性时态，比如上面句中的could。当然还可以用will,would,can,等。

2、so that既可引导目的状语从句，也可以引导结果状语从句。

1)其引导结果状语从句时，so that翻译为“以至于...”，经常可以和

so/such...that...转换，且从句只能放在主句之后。如：he got up late so that he was late for school. = he got up so late that he was late for school.

2)其引导目的状语从句时，从句只能放在主句之后，此时可以和in order that换用。如：he got up early so that he could take the first bus. = he got up early in order that he could take the first bus.

常见考法

对于目的状语从句的考查，多以单选和完形填空的形式，从连词的

意义角度让大家选择连词。

典型例题：ann listened carefully _____ she could discover

what she needed.

a. such that

b. in order that

c. because

d. even though

解析：题干的意思是“为了能够发现自己需要的东西，安认真听讲”。很明显从句表示的是目的。such that本身是错误短语，because 表示原因，even though是“尽管”的意思，不符合题意。

答案：b

误区提醒

如何区别目的状语从句中的so that与结果状语从句中的so that的

用法，这是我们需要注意的。目的状语从句的so that是连着的，结

果状语从句是分开的，即so…that. so that是目的状语从句，是为

了什么什么，有目的的含义。而so…that是结果状语从句，是“如

此怎么怎么样结果是什么”。仔细体会一下吧!

典型例题：i get up so early i can not be late

a. that b . so that c.such that d.in order

解析：题干的意思是“我起床如此早以便于我可以不迟到”。从句表

示目的，首先排除c，因为such that本身是错误短语，在排除in

order，因为它后面不能跟句子;因为句子中有so,所以大家可能选a，如果选它，那句子的意思是“我起床如此早结果我可以不迟到”，显

然说不通，所以排除。

答案： b

三、例题精析

【例题1】