问题 选择题

如图所示,带箭头的直线是某电场中的一条电场线,在这条线上有A、B两点,用EA、EB表示两处的电场强度,则(  )

A.EA>EB

B.EA=EB

C.EA<EB

D.无法确定

答案

电场线的大小由电场线的疏密表示,由于A、B附近电场线的分布情况未知,一条电场线无法判断疏密,则EA、EB的大小不能确定.

故选D.

阅读理解

请认真阅读下面短文,并根据短文内容回答问题。

Zhang Li lies in bed sadly. The 24-year-old young man lost his right leg because of a blood disease (血液病). The doctor said that his 10 years of smoking had caused the disease.

“I first smoked a cigarette when I was in Junior 3. It made me feel like a man and I thought it looked cool. Now I know I was really wrong,” said Zhang.

According to the 2008 China Tobacco Control report (中国烟草控制报告), 130 million young people who are under 18 years old have tried smoking. Fifteen million of them are addicted (上瘾的).

The report came out on May 31, World No-Smoking Day. It also found that nearly 68% of teenage smokers smoked their first cigarette before the age of 13. Those living in big cities started even earlier.

“Some tobacco companies try to make cigarettes cool and attractive. It’s just to make money,” said Yang Gonghuan, a doctor. In fact, smoking is one of the top killers in China. Each year 1 million people die from smoking-related (与吸烟有关的) diseases. Smoking causes illnesses like lung cancer and heart disease.

Doctors say that the younger a person starts smoking, the worse it will be. If a person starts smoking as a teenager, he or she may live twenty-two years less than non-smokers. 

回答下列问题

小题1:What caused Zhang Li’s disease?

小题2:When did he first smoke a cigarette?

小题3:How many people die from smoking-related diseases each year in China?

小题4:If someone smokes too much, what diseases can he develop?

小题5:Why do many teenagers smoke at first? (请自拟一句话作答,最好用文中句子改写)

填空题