问题 单项选择题

某商店搞店庆,购物满198元可以抽奖一次。一个袋中装有编号为0到9的十个完全相同的球,满足抽奖条件的顾客在袋中摸球,一共摸两次,每次摸出一个球(球放回),如果第一次摸出球的数字比第二次大,则可获奖,则某抽奖顾客获奖概率是( )

A.5%

B.25%

C.45%

D.85%

答案

参考答案:C

解析:【解析】C。如果摸到0,则中奖概率为90%,如果摸到1,则中奖概率为80%,其余依次为70%,60%,50%,40%,30%,20%,10%,0%,将这10个概率取平均数,则中奖总概率为45%。

阅读理解

“I sometimes get up at three or four in the morning and I surf the net.”

“I often check my e-mail forty times a day. ”

“I often spend more than three hours during one time on the net.”

“I spend more time in chat rooms than with my ‘real-life’ friends.”

Do you know any people like these? They are part of a new addiction(上瘾)called Internet addiction. Internet addicts spend at least thirty to forty hours online every week. The use of the Internet can be an addiction like drug(毒品)use. People lose control(控制)of the time they spend on the Internet.

For example, one college student was missing for several days. His friends were worried, and they called the police. The police found the student in the computer lab: he was surfing the net for several days straight.

Studies show that about 6% to 10% of Internet users become addicted. And people worry about the teens because the Internet is changing the playing field for some of them. They spend more time in cyberspace than in the real world of friends and family.

Is “surfing the net” a hobby or an addiction for you? You may have a problem if you have these symptoms(症状):  ①You do not go to important family activities or you do not do school work because you like to spend hours on the Internet.  ②You can’t wait for your next online time.   ③You go out with your friends less and less.   ④You plan to spend a short time online, but then you spend several hours.

小题1:How does the writer describe the addicts’ use of Internet?

A.It is something like keeping drugs.

B.It is like taking drugs.

C.It is a way of producing drugs.

D.It is terrible to imagine.小题2: Why do people worry about the teens?

A.The teens are wasting too much money.

B.They used to work on the Internet.

C.The playing field of the teens will disappear.

D.More and more of the teens will become addicted to the Internet.小题3:The example in the passage shows that     .

A.some of the Internet users have already been seriously addicted

B.Internet addicts usually stay in the computer lab without sleep

C.Internet problems are more serious among college students

D.the police often help to find those Internet addicts小题4:What is the writer trying to tell us at the end of the passage?

A.Do things as you have planned.

B.Go to family activities more often.

C.Don’t be addicted to the Internet.

D.Stay with your parents as often as possible.

填空题