本篇阅读材料“美国小孩受电视的间接影响很大”选自《时代》（原文标题：American Kids Exposed to Too Much Background TV: Study 2012.4.20）。

　　Too much television can be detrimental for kids’ development, even when they’re not plopped directly in front of the screen. And your kids might be getting more exposure to such background TV than you think, a new study finds.
　　The researchers found that the average American kid was exposed to 232.2 minutes of background television per day — when the TV was on, but the child was engaged in another activity. Younger children and African-America children were exposed to the most background television on average.
　　"We were ready and willing to accept that the exposure would be high, but we were kind of shocked at how high it really was,” says study author Matthew Lapierre, a doctoral candidate and lecturer at the University of Pennsylvania’s Annenberg School for Communication. “The fact that kids are exposed to about four hours on average per day definitely knocked us back on our heels a bit.”
　　knock back 使……大吃一惊
　　Previous research has found that exposure to background television is linked to lower attention spans, fewer and lower-quality parent-child interactions and reduced performance in cognitive tasks, the authors said in the study.
　　attention span 注意力持续时间
　　The current findings came from data gathered in a nationally representative telephone survey of 1,454 American parents with at least one child between the ages of 8 months and 8 years. The parents were asked about how often their TV was on when no one was watching and whether their child had a TV in their bedroom.
　　"For every minute of television to which children are directly exposed, there are an additional 3 minutes of indirect exposure, making background exposure a much greater proportion of time in a young child’s day,” the authors say in the study.
　　What they found even more concerning was that kids under 2 and African-American children are exposed to 42% and 45% more background TV, respectively, than the average child.
　　"It’s particularly concerning because there is evidence this exposure has negative consequences for development,” says Lapierre. According to the authors, these high rates could be the result of parents not counting background TV as exposure or thinking their kids are too young to be affected by it.
　　"This study should be a warning to parents and day-care providers to shut off the television when no one is watching, and certainly to consider the consequences of having a television in a child’s bedroom no matter how young they may be,” said Cynthia Stohl, the International Communication Association president and professor of communication at the University of California, Santa Barbara, in a statement.
　　The researchers are hopeful their findings will further the understanding of how home media practices relate to background television exposure, so recommendations for reducing kids’ exposure can be made.
　　The new data will be presented at the International Communication Association’s annual conference in Phoenix next month.

　　Question time:
　　1. According to previous research, What does exposure to background television result in?
　　2. What does the word "concerning" mean in Para. 7?
　　3. What should parents do in order to decrease the negative consequences of exposure to Television?