I’m usually fairly skeptical about any research that concludes that people are either happier or unhappier or more or less certain of themselves than they were 50 years ago. While any of these statements might be true, they are practically impossible to prove scientifically. Still, I was struck by a report which concluded that today’s children are significantly more anxious than children in the 1950s. In fact, the analysis showed, normal children ages 9 to 17 exhibit a higher level of anxiety today than children who were treated for mental illness 50 years ago.
　　Why are America’s kids so stressed? The report cites two main causes: increasing physical isolation—brought on by high divorce rates and less involvement in community, among other things—and a growing perception that the world is a more dangerous place.
　　Given that we can’t turn the clock back, adults can still do plenty to help the next generation cope.
　　At the top of the list is nurturing (培育) a better appreciation of the limits of individualism. No child is an island. Strengthening social ties helps build communities and protect individuals against stress.
　　To help kids build stronger connections with others, you can pull the plug on TVs and computers. Your family will thank you later. They will have more time for face-to-face relationships, and they will get more sleep.
　　Limit the amount of virtual (虚拟的) violence your children are exposed to. It’s not just video games and movies; children see a lot of murder and crime on the local news.
　　Keep your expectations for your children reasonable. Many highly successful people never attended Harvard or Yale.
　　Make exercise part of your daily routine. It will help you cope with your own anxieties and provide a good model for your kids. Sometimes anxiety is unavoidable. But it doesn’t have to ruin your life.

　　21. The author thinks that the conclusions of any research about people’s state of mind are ________.
　　A) surprising
　　B) confusing
　　C) illogical
　　D) questionable（D）

　　22. What does the author mean when he says, “we can’t turn the clock back” (Line 1, Para. 3)?
　　A) It’s impossible to slow down the pace of change.
　　B) The social reality children are facing cannot be changed.
　　C) Lessons learned from the past should not be forgotten.
　　D) It’s impossible to forget the past.（B）

　　23. According to an analysis, compared with normal children today, children treated as mentally ill 50 years ago ________.
　　A) were less isolated physically
　　B) were probably less self-centered
　　C) probably suffered less from anxiety
　　D) were considered less individualistic（C）

　　24. The first and most important thing parents should do to help their children is ________.
　　A) to provide them with a safer environment
　　B) to lower their expectations for them
　　C) to get them more involved socially
　　D) to set a good model for them to follow（C）

　　25. What conclusion can be drawn from the passage?
　　A) Anxiety, though unavoidable, can be coped with.
　　B) Children’s anxiety has been enormously exaggerated.
　　C) Children’s anxiety can be eliminated with more parental care.
　　D) Anxiety, if properly controlled, may help children become mature.（C）