Computer English test

Reading comprehension

What Is a Network?

Throughout the world, your microcomputer can connect to other microcomputer, to the internet, and to larger computer through the electronic communication systems.

The electronic communication systems transmit information over communication lines of cable and air from one location to another. Such electronic communication lines are known as networks.

A network can be arranged in several different ways to meet different users’ need. The network arrangement is called the network’s topology. The four principal topologies are star, bus, ring, and hierarchical.

In a star network, a number of small computers or peripheral devise are linked to a central unit-maybe a host computer or a file sever. The host computer maintains its control by asking whether each connected devise has messages to send. One disadvantage of the star network is that several users can share resources on a central host computer.

In a bus network, there is no host computer, and instead each devise in the network handles its own communication control. This arrangement is common for sharing data stored on different microcomputers but not as efficient as the star network for sharing common resources.

In a ring network, each device is connected to two other devices, forming a ring. There is no central computer or file server. Messages are passed around the ring until they reach the correct destination. With microcomputers, the ring arrangement is the least frequently used of the four networks. It is often used to link mainframe computers, especially over wide geographical areas.

The hierarchical network consists of several computers lined to a central host computer, just like a star network, but those other computers are also hosts to other smaller computers. A hierarchical network is useful in centralized organizations. For example, different departments connected to departmental minicomputer and the minicomputer in turn may be connected to the corporation’s mainframe, which contains data and programs accessible to all.

Geographically, using both cable and air connections, networks arrange from home to citywide and even international. Here let us have some idea of three types: local area network, metropolitan area network, and wide area network.

Networks with computers and other devices in close physical proximity-within the same building, or on the same campus, for instance- are called local area networks (LANs). Linked by cable-telephone, co-axial, or fiber-optic-LANs often use a bus form of organization. A LAN may be linked to other LANs or to larger networks.

A step up from the LAN is the MAN—the metropolitan area network. These networks are used as links between offices building in a city. Cellular phone systems expand the flexibility of MANs by allowing links to car phone and portable phones.

Wide area networks (WANs) are countrywide and worldwide networks. Besides cable, they use microwave relays and satellites to reach users over long distances. The

widest of all WANs is the Internet, which spans the entire globe.

1.How many principal network topologies? ( )

A. 2

B. 3

C. 4

D. 5

2. The principal network topologies are____________?

A. bus, ring, star, hierarchical,

B. cross, bus, ring, hierarchical,

C. ring, star, straight, hierarchical,

D. rainbow, ring, bus, cross,

3. Which two have no host computer? ( )

A. star, ring,

B. hierarchical, bus,

C. ring, star,

D. ring, bus

4. The widest of all _____is the Internet, which spans the entire globe.

A. W AN,

B. MAN,

https://www.360docs.net/doc/1617276169.html,N,

D. SAN,

5. Which one is true? ( )

A. bus

B. ring

C. hierarchical

D. star

6. How many geographical network types?

A. 2

B. 3

C. 4

D. 5

7. The geographical network types are_______?

A. W AN, LAN, MAN,

B. W AN, SAN, LAN,

C. SAN, W AN, MAN,

D. LAN，SAN, W AN

连线题：

（1）topology （）移动电话系统

（2）handle （）跨越

（3）geographical （）继电器

（4）metropolitan （）拓扑

（5）transmit （）微波

（6）accessible （）处理

（7）microwave （）大城市的

（8）span （）可达到的

（9）relay （）传输

（10）cellular phone system （）地理的

（11）fiber-optic （）光纤的

填空题：请在下面专业术语的后面填上正确的中文意思

（1）central unit ________________ （2）Local area network(LAN) _________________ （3）Metropolitan area network(MAN) __________________ （4）Wide area network(W AN) __________________ （5）electronic communication system _________________ （6） a bus network __________________ （7） a ring network __________________ （8） a hierarchical network __________________ （9） a star network __________________ （10）file server __________________ （11）peripheral device __________________ （12）a host computer __________________ （13）personal computer(PC) __________________ （14）relay __________________ （15）mainframe __________________