如图所示,开关S闭合后,电路正常工作,电压表有一定的示数。一段时间后,电压表的示

题型:填空题

问题:

如图所示,开关S闭合后,电路正常工作,电压表有一定的示数。一段时间后,电压表的示数突然变为零,则故障可能是R1_______或R2_______。(填“短路”或“断路”)

考点:电路故障分析
题型:填空题

阅读理解。

     The Internet is a big place. Nobody has the time to look at every webpage to find something. Search

engines (搜索引擎) like Yahoo give us a lot of help.

     Two Stanford University students, David Filo and Jerry Yang started it in 1994. They made a list of

their favorite webpages. When their list got bigger, they made a database (数据库) to keep all the

information. They let everyone use it for free. Soon, thousands of people were using it.

     They then made a new kind of software (软件). It looked at web pages all over the Internet. It could

then take that information and arrange it for someone to look at. If you look for "animals", the engine will

give you a list of web pages with those words.

      Yahoo became a public (公共的,公开的) company in 1996. Filo and Yang, still young men, became

rich. As the company grew, they went on working hard. They improved the software. They also put

more uses in, like shopping, free E-mail, booking tickets and so on. They started Yahoo in many different

countries and languages.    

     Yahoo. Com is famous on the Internet. And unlike most other web companies, Yahoo really makes

money.

1. When Yang and Filo wrote the first Yahoo software, they _____. [ ]

A. made people to use it

B. were still university students

C. knew it wasn't useful

D. were high school students

2. After Yang and Filo became rich, they _____.[ ]

A. became lazy

B. worked less

C. kept working hard

D. stopped working at Yahoo

3. What Yahoo services (服务) are not mentioned in the passage? [ ]

A. Buying and selling stocks.

B. Search engine.

C. E-mail.

D. Booking tickets.

4. Which of the following is true? [ ]

A. Yahoo was always a big company.

B. Yahoo is a private company.

C. Yahoo does not make people pay for their E-mail service.

D. Yahoo is losing money.

5. What does the passage think of most Internet companies? [ ]

A. They don't earn much money.

B. They are all famous.

C. They are just like Yahoo.

D. They are all in English.

题型:填空题

如图所示,光线AO入射到平面镜上,请根据光的反射定律作出反射光线.

题型:填空题

保税仓库的设立需要专门批准,外国货物的保税期一般最长为(),在这个时期中可存放在保税仓库中。

A.2年

B.3年

C.5年

D.1年

题型:填空题

二里头文化时期的陶器上出现了()。

A.陶文

B.金文

C.甲骨文

D.绳纹

题型:填空题

第二部分

今天我骑自行车去学校。()

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