问题 填空题

电路有三种状态:(1)通路:______的电路叫通路;(2)开路:______的电路叫开路;(3)短路:直接把导线接在______上的电路叫短路.

答案

处处连通的电路叫做通路;某处断开的电路叫做开路,也叫断路;电源短路是将导线直接接在电源正负两极上的电路.

故答案为 处处连通;断开;电源负极两极.

阅读理解

阅读下文,从各小题所给的四个选项中选出能回答所提问题或完成所给句子的最佳答案。

       When you want to find some information, do you first think of the Internet? Now, more and more

students are using the Internet instead of using books. But we can't completely believe the Internet.

       Even though it's quick and easy to find information online, many online sources may not be true, for

anyone can publish a web page or website. That's why we must consider the following before deciding

whether or not to use the information:

       * Use sites that end with . edu,  . com,  . gov, or . org.

       * Use the latest information you can find.

       * Make sure the writer of the article or site is credible(可信的) .

       * Does the writer list his or her qualifications(授权)  to write on the subject? Have you seen this

writer's work before?

       * Where did the writer get his or her information? Did the writer get it from first-hand sources or

another expert? If the writer doesn't say where the information came from, don't use it.

       * Who is publishing the site? What are the writer's goals in publishing information?

       If you're not sure about a source, it's always best to check with a parent or teacher. When using an

online source, make sure you cite(引用) the source so that your readers know where you got your

information.

1. More and more students use the Internet to find information because________.       

A. information on the Internet is always true

B. it's quick and easy to find information online

C. there're different kinds of information on the Internet

D. using books is too slow for them to find information

2. The writer tells us to choose __________ .        

A. any information online

B. any information in the book

C. some the latest information always

D. some credible information

3. Which of the following is TRUE?      

A. Not all people can have his own website.

B. Readers don't trust the information online.

C. Many information on the Internet isn't true.

D. The writer tells us to use all information online.

4. The meaning of the word 'source" is__________ . 

A. 谣言        

B. 政策  

C. 书籍    

D. 资源

5. The passage mainly tells us how to_________.         

A. find credible information on the Internet

B. chat with people on the Internet

C. protect our personal information

D. learn every subject online

单项选择题 A1/A2型题