阅读理解。

     This is a dangerous world we live in. The number of murders goes up every year,

people are dying of cancer, more people contract (感染)HIV, more teens are using

drugs, etc. You know this because you've heard all the statistics on the news and in

the paper. But do you really have an accurate idea what they mean? The numbers

are going up, but how do they compare to the growth in population? Are more cases

of these diseases being reported because of better testing techniques, or are the

diseases more common? The fact is that without knowing the background statistics

mean very little.

     This growing trend of reporting only part of the information is becoming dangerous.

For example, several years ago a high school student reported the dangers of the

chemical known as dihydrogen monoxide. This chemical,found in most cancerous

umors(肿瘤 ) ,is often found in the blood of people drunk on alcohol, and causes

complete physical and mental dependence for those who take the chemical even once.

After reading his report, more than 75% of his Advanced Placement Chemistry class

voted to forbid this dangerous chemical! Every one of the above statements is true,

yet this chemical is necessary to all life on earth. The students made the mistake

because they voted knowing only a few statements and statistics, rather than the

chemical's full background.

     The point of this article is that one should be aware of what is and is not being

said. When one finds a new fact or number , one should try to consider other

important information before forming an opinion with only half-truths. Always

remember that the author is trying to convince you of his or her own view, and

will leave out information that is different to his view. For example, look again at

the statistics that suggest skiing is safe. Only 32 people may die each year when

skiing, while 897 die from lightning strikes, but which is really the most dangerous?

If you think about it, you realize far fewer people go skiing each year than the number

of people who are in danger of a lightening strike. When you think about it ,skiing

is more dangerous than you might at first think when looking at statistics. lf we

teenagers are to be left this world. we had better be able to think critically, and

form our own views, rather than be easily persuaded by another's. To be warned

is to be prepared.

1. In the first paragraph, what problem does the writer want to warn us?______

A. We are now living in a dangerous world.

B. We get a lot of' false statistics from the media.

C. There are around us more and more murders,diseases etc.

D. Statistics alone without full background doesn't give us an accurate picture of things.

2. Why does the writer use the example in the second paragraph ? .______

A. To show the danger of reporting only part of the information.

B. To argue that high school students are easily persuaded.

C. To prove what is necessary to us might be dangerous.

D. To warn us of the harmful substance around us.

3. Relative information is often left out because ______.

A. relative information is not that important

B. the author is trying to show what he or she says is true

C. too much information will make readers feel confused

D. readers are not able to analyze so much information at once

4. What can we learn from the passage?_____

A. Some measures must be taken to protect our dangerous world.

B. We should leam to think critically and look at problems from all sides.

C. The growing trend of reporting only half-truths is getting out of control.

D. Teenagers ought to improve their ability of telling right from wrong