Having a teenager at home can be a real headache. Many teenagers smoke, wear strange hairstyle and even fight. Basically (基本上) , they are often taking risks.

Earlier studies have shown that teenagers are more likely to make irrational decisions than people from any other age group, including children and adults. Is it that teenagers are too young to tell right from wrong? Not really. So what’s the reason?

According to Laurence, a teacher from a US university, the reason is that teenagers care a lot about how their peers (同龄人) view them—that is “peer influence”.

As children enter their teenage years, they spend more time with their friends and classmates, and also they care more about what they think of them. This makes teenagers make decisions without thinking about the costs.

In a test, a group of teenagers were asked to play a video driving game. When they played with their friends watching around them, they took more chances and drove more carelessly because that would increase their possibility of winning. But when they played alone, they drove more safely.

Why do peers have such a big influence on teens’ behavior?

As Laurence sees it, a teenager’s brain is like a car with a good accelerator (油门) but a weak brake (刹车). The “accelerator” is fully developed by teenage years while the “brake” is still not fully developed. When teenagers are watched by their peers, they usually push hard on the accelerator. With their weak brake, it is likely that they are going to end up in an accident. But the good news is that a violent (暴力的) teenager doesn’t necessarily become a violent adult. About two-thirds to three-quarters of violent youth grow out of it. “They get more self-controlled.”

小题1:What does the underlined word “irrational” in the 2nd paragraph mean?

A．Quick.

B．Crazy.

C．Careful.

D．Correct.小题2: Why are teenagers often taking risksaccording to the text?

A．They like difficult tasks.

B．They don’t care about costs.

C．They are too young to tell right from wrong.

D．They care a lot about what their peers think of them.小题3:How does Laurence explain the influence of peer influence on teens’ behavior?

A．By using a metaphor (比喻).

B．By giving examples.

C．By presenting research findings.

D．By performing an in-depth analysis (分析).小题4:According to the text, with peers around them, teenagers tend to (倾向于) ______.

A．use more self-control

B．become more careful about what they do

C．perform better than when they are alone

D．focus more on short-term benefits（利益）小题5:What can we learn from the text?

A．Teenagers are easy to have traffic accidents.

B．Peer influence is bad on teenagers.

C．Most of the teenagers become less violent when they grow up.

D．Teenagers shouldn’t spend all the free time with their friends.