问题 选择题

在如图所示的四种情况中,符合安全用电要求的是

答案

答案:C

题目分析:安全用电的基本原则是不接触低压带电体,不靠近高压带电体;生活用水是导体;有金属外壳的家用电器,使用时金属外壳要接地;为了安全起见,控制用电器的开关与火线相连;电路中电流过大的原因有两个:一是短路;二是家中使用用电器的总功率过大。

A、将手插入插座内,会有电流传到人体上,使人体触电,十分危险。不合题意。

B、家用电器的金属外壳要接地,防止金属外壳漏电,发生触电事故,不合题意。

C、家庭电路中,开关要串联在火线和电灯之间,符合题意。

D、电路中电流过大的原因有两个:一是短路;二是家中使用用电器的总功率过大.故大功率用电器同时使用时,将会使电路中的电流过大,引起火灾。不合题意。

故选C。

点评:本题考查了安全的常识,我们要不接触低压带电体,不靠近高压带电体。

阅读理解

People are being lured (引诱)onto Facebook with the promise of a fun, free service without realizing they're paying for it by giving up their personal information. Facebook then attempts to make money by selling their data to advertisers that want to send targeted messages.

Most Facebook users don't realize this is happening. Even if they know what the company is up to, they still have no idea what they're paying for Face book because people don't reallyknow what their personal data is worth.

The biggest problem, however, is that the company keeps changing the rules. Early on, you keep everything private. That was the great thing about facebook-you could create your own little private network. Last year, the company changed its privacy rules so that many things— your city, your photo, your friends' names—were set, by default(默认)to be shared with every one on the Internet.

According to Facebook's vice-president Elliot Schrage, the company is simply making changes to improve its service, and if people don't share information, they have a "less satisfying experience".

Some critics think this is more about Facebook looking to make more money. In original business model, which involved selling ads and putting them at the side of the pages totally. Who wants to look at ads when they're online connecting with their friends?

The privacy issue has already landed Facebook in hot water in Washington. In April. Senator Charles Schumer called on Facebook to change its privacy policy. He also urged the Federal Trade Commission to set guidelines for social-networking sites. "I think the senator rightly communicated that we had not been clear about what the new products were and how people could choose to use them or not to use them," Schrage admits.

I think that whatever Facebook has done so far to invade our privacy, it's only the beginning. That is why I'm considering deactivating(撤销)my account. Facebook is a handy site, but I'm upset by the idea that my information is in the hands of people I don't trust. That's too high a price to pay.

小题1:Why do people give their personal information to Facebook according to Paragraph 1?

A.Because they can get some money from Facebook.

B.Because their information is not important.

C.Because they are promised to have a fun and free service.

D.Because they can also get other people's information.小题2:What does the author say about most Facebook users?

A.They are unwilling to give up their personal information.

B.They don't know their personal data enriches Facebook.

C.They don't identify themselves when using the website.

D.They care very much about their personal information.小题3:Why does Facebook make changes to its rules according to Elliot Schrage?

A.To give better service to its users.

B.To obey to the Federal guidelines.

C.To improve its users' connection.

D.To expand its business.小题4:Why does Senator Charles Schumer support publicly?

A.Setting guidelines for advertising on websites.

B.Banning the sharing of users' personal information.

C.Making regulations for social-networking sites.

D.Removing ads from all social-networking sites.

单项选择题