单选题 What we don"t know about kids and television could fill a weeklong miniseries. Given worries about everything from childhood obesity to scholastic shortcomings, it"s high time to find out. But before Congress approves $20 million. a year to research children and the media, it should get more specific assurances that the money will pay for comprehensive, high-quality studies instead of bits of teasing information.
Up to now, a patchwork of research on kids and TV has yielded plenty of suspicion but little real knowledge. Yes, a study two years ago found that teenagers who watched a lot of TV tended to be more aggressive. But what does that mean? Maybe more-aggressive kids are drawn more to TV. Ditto for the April study about preschoolers who watch hours of TV tending to have attention-span problems later on. It"s possible that children with a propensity toward attention problems are drawn more to that jumpy on-screen world in the first place.
For better or worse, U.S. kids spend a lot of time in front of a TV or computer screen, two hours daily for those 5 and younger. If the schools spent two hours a day on a single activity, there would be intense concern about its value.
So there is worth in legislation by Sen. Joe Lieberman to provide $100 million over five years for research on child development and electronic media. A scientific panel would set up a list of the key issues to be studied and review grant applications from universities or nonprofit institutes. This centralized approach makes sense—especially considering the money involved.
Good studies are costly, and there haven"t been enough of them on this subject. Merely showing a link between TV viewing and a certain behavior doesn"t prove anything. In addition to the possibility the behavior is causing the TV watching instead of the other way around, a third factor could be causing both. Only carefully controlled studies obtain worthwhile results.
At their best, such studies might tell us whether educational computer games for toddlers interrupt the natural development of the brain instead of aiding it, or whether seeing Ronald McDonald cavort on a soccer field makes a child more active or just more likely to crave French fries. Parents could decide limits based on more than instinct.
But before spending the money, Congress should insist on a quality of research that will give the public answers about TV instead of more arguments. This shouldn"t be a handout to think tanks for more mushy research on a complicated but vital issue.

单选题 The purpose of the author in writing this passage is ______.

单选题 We can infer from the passage that ______.

单选题 The word "propensity" in Paragraph 2 is probably closest in meaning to ______.

单选题 Too much viewing of TV may cause the following problems EXCEPT ______.

单选题 The author tries to suggest that ______.