问题 选择题

下列叙述错误的是(  )

A.分子都是由原子构成的

B.原子如果得到或失去电子就变成离子

C.在化学变化中分子可以分解,原子也可以分解

D.原子中原子核与核外电子的电量相等,电性相反,因而原子不显电性

答案

A、分子都是由原子构成的.A叙述正确;

B、原子通过得到或失去电子,就变成带电的原子,带电的原子属于离子.B叙述正确;

C、在化学变化中分子可以分解,原子不可以分解.C叙述错误;

D、原子中原子核带正电,核外电子带负电,电量相等,电性相反,因而原子不显电性.D叙述正确.

故选C.

阅读理解

Perhaps you have heard a lot about the Internet, but what is it, do you know? The Internet is a network. It uses the telephone to join millions of computer together around the world.

Maybe that doesn’t sound very interesting. But when you are joined to the internet, there are lots and lots of things you can do. You can send e-mail to your friends, and they can get them in a few seconds. You can also do with all kinds of information on the World Wide Web (WWW).                                              

There are many different kinds of computers now. They all can be joined to the internet. Most of them are small machines sitting on people’s desks at home, but there are still many others in schools, offices, or large companies. These computers are owned by people and companies, but no one really owns the internet itself.

There are lots of places for you to go into the internet. For example, your school may have the internet. You use it during lessons or free time. Libraries often have computers joined to the internet. You are welcome to use it at any time.

Thanks to the internet, the world is becoming small. It is possible for you to work at home with a computer in front, getting and sending the information you need. You can buy or sell what ever you want by the internet. But do you know 98% of the information on the internet is in English? So what will English be like tomorrow?

小题1:What is the passage mainly about?

A internet     B information       C computers       D E-mails

小题2:Which is the quickest and cheapest way to send messages to your friends?

A by post     B by e-mail       C by telephone     D by satellite

小题3:Which may be the most possible place for people to work tomorrow?

A in the office     B at school     C at home    D in the company

小题4:Who is the owner of the internet?

A The headmaster    B The officer     C The user      D No one

小题5:What does the writer try to tell us with the last two sentences?

A English is important in using the internet.

B The internet is more and more popular.

C Most of the information is in English.

D Every computer must have the internet.

单项选择题