问题 选择题
如图所示,AB是一质量为m的均匀细直杆,A端靠在光滑的竖直墙壁上,B端置于水平地面上,杆身与竖直方向夹角为θ,杆与地面的摩擦系数为μ,保持平衡,则此时杆与地面的摩擦力为(  )

A.mgtgθ

B.mgsinθ

C.μmg

D.μmg

答案

答案:A

阅读理解

A new generation addiction is quickly spreading all over the world. Weboholism, a twentieth century disease, affects people from different ages.They surf the net, use e-mail and speak in chat reoms. They spend many hours on the computer, and it becomes a compulsive habit. They cannot stop, and it affects their lives. 

Ten years ago, no one thought that using computers could become Compulsive

behavior that could affect the social and physical life of computer users. This obsessive behavior has affected teenagers and college students. They are likely to log on computers and spend long hours at different websites.

They become hooked on computers and gradually their social and school life is

affected by this situation. They spend all free time surfing and don't concentrate on homework, so this addiction influences their grades, and success at schools. Because they can find everything on the websites, they hang out there. Moreover, this addiction to websites influences their soeial life.

They spend more time in front of computers than with their friends. The relation with their friends changes. The virtual life becomes more important than their real life. They have a new language that they speak in the chat rooms and it causes cultural changes in society,

Because of the change in their behavior, they begin to isolate themselves from the society and live with their virtual friends. They share their emotions and feelings with friends Who they have never met in their life.Although they feel confident on the computer, they are not confident with real life friends they have known all their fife. lt is a problem for the future. This addictive behavior is beginning to affect the whole world.

小题1: The passage is about               

A.the cause of weboholism

B.the advantage of weboholism

C.the popularity of weboholism

D.the influence of weboholism小题2:The underlined word"obsessive" in the second paragraph most probably means    

A.attractive

B.addictive

C.professional

D.potential小题3: We can learn from the passage that               .

A.weboholism has the greatest effect on teenagers

B.teeangers can hardly balance real and virtual life

C.people are addicted to games on the lnternet

D.virtual life is more vivid and attractive anyway小题4: Which of the following is NOT true of weboholism?

A.It contributes to the development of the web.

B.The chat room language may change social culture.

C.The problem will have a negative influence on our future.

D.People addicted to the web often become inactive in real life.小题5:The author's attitude towards weboholism is that of being         

A.objective

B.positive

C.opposed

D.acceptable

填空题