Parents may be surprised at how fast their kids grow up, but a study finds that U. S. teenagers are developing more slowly than those in the past.
Scientists at San Diego State University have worked on a study of over 8 million U. S. kids aged 13-19 for 40 years. The findings show that today's teenagers are less responsible(负责任的) and that most of them don't have a part-time job. "The whole development has slowed down. Today's 18-year-olds are more like 15-year-olds in the past, " said Professor Jean Twenge. "Teenagers are taking fewer risks than those in the past. "
Scientists have also found that more teenagers spend longer time living with their parents instead of renting(租)their own room or apartment. So is that slower development "good" or "bad"? It may depend on how you look at it, the scientists said. "The upside of slower development is that teenagers aren't growing up before they are ready, " said Professor Twenge. "But the downside is that they go to college and into the workplace without as much experience with independence. Today's students may be smart and creative, but they often have trouble with planning, time management (管理) and problem-solving, "added Professor Twenge.
One of the reasons for these changes is that today's teenagers would like to spend much time online. They keep on watching videos or playing games on the Internet instead of spending more time with their family and friends in person. Another one is that parents have become much more "child-centric". In fact, parents had better let their children do everything by themselves. They should try their best to make their children become independent as soon as possible.
a. Their parents do too many things for them.
b. It's difficult for them to get a part-time job.
c. They dislike living in the real world.
d. They spend too much time online.
B . 
C . 
D . 
