如图所示，电阻R1和R2的阻值分别为20Ω和10Ω，电源电压保持6V不变．当开关

给下面多音字注音并组词。

①呵（     ）________

　　（     ）________

②还（     ）________

　　（     ）________

We are all busy taking 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, computers were large and expensive. 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.

At first the Internet was only used by the government (政府). 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. Scientists had also developed software that made “surfing” the Internet more convenient.

Today it is easy to get on-line and it is said millions of people use the Internet every day. Sending e-mails is more and more popular among students.

The Internet has now become one of the most important parts of people’s life.

小题1:The Internet has a history of more than _________ years.

A．fifty

B．ten

C．forty

D．twenty小题2:A new network system was set up to_______.

A．make computers cheaper

B．make itself keep on working all the time

C．break down the whole networks

D．make computers large and expensive小题3: At first the Internet was only used by __________.

A．the government

B．universities

C．hospital and banks

D．schools小题4: ________ made “surfing” the Internet more convenient.

A．Computers

B．Scientists

C．Software

D．Information小题5: Which of the following sentences is true?

A．In the 1960s, computer networks worked well

B．In the early 1970s, the Internet was easy to use.

C．Sending e-mails is more popular among students than before.

D．Today it is still not easy to get on-line.

在医疗保险中，为了加强被保险人对医疗费用的自我控制，（）成为最常用的条款。

A.免赔额条款

B.贷款条款

C.宽限期条款

D.免责条款

关于晨僵，最正确的说法是（）

A.仅见于类风湿关节炎

B.见于大多数类风湿关节炎

C.见于大多数类风湿关节炎，也见于其他疾病

D.见于少数类风湿关节炎

E.仅见于类风湿关节炎晚期

设 ，则（）。

A．

B．a=0，b=-2

C．

D．a=1，b=-2