问题 多项选择题

电力变压器结构形式按绝缘介质可分为()。

A.油浸式变压器

B.水冷却变压器

C.空气冷却变压器

D.干式变压器

答案

参考答案:A, D

阅读理解

阅读理解。根据短文内容,判断正(T) 误(F)。

  We are all busy talking about and using the Internet,but how many of us

know the history of the Internet?Many people are surprised when they find that

the Internet was set up in the 1960s.At that time,computer networks didn't work

well.If one computer in the network broke down, then the whole network stopped.

So a new network system had to be set up.It should be good enough to be used by

many different computers.If part of the network was not working,information

could be sent through another part.In this way computer network system would

keep on working all the time,I'm daydaytest Placeholder

  At first the Internet was only used by the government, but in the early 1970s,

universities, hospitals and banks were allowed to use it, too. However, computers

were still very expensive and the Internet was difficult to use.By the start of the

1990s,computers became cheaper and easier to use.Scientist had also developed

software (软件) that made "surfing" the Internet more convenient (方便的).

  Today it is easy to get on-line and millions of people use the Internet every

day. Sending e-mail is more and more popular among people.

  The Internet has now become one of the most important parts of people's

life.

( )1. The Internet has a history of less than thirty years.

( )2. In the 1960s computer networks went wrong easily.

( )3. Scientists set up a new network system to make computers cheaper.

( )4. I'm daydaytest Placeholder!People didn't have enough software to get

on-line conveniently until the early 1990s.

( )5. The Internet is only easily used by governments,banks,offices and

universities.

单项选择题