Watching television makes it easier for toddlers（学走路的孩子）to kick and scream, according to a U.S. study. Children under two should not watch any TV. The longer they sit in front of the box, the worse their behavior becomes.
Just having the TV on in the background, even if the child wasn’t watching it, was also connected to troublemaking behavior although the relationship wasn’t as strong, said the researchers.
“Parents should be smart about TV use,” researcher Jennifer Manganello from the University at Albany, New York, said.
“They should limit the time that children use TV, pay attention to the content of TV programs, and consider how TV is used throughout the home.”
The study looked at 3,128 women from 20 U.S. cities who had a child between 2005 and 2008.
While there was some diversity（差异）of education among the women, one-third hadn’t graduated from high school.
Two-thirds of the mothers said their three-year-old watched more than two hours of TV a day, and the average（平均的）viewing time for children was around three hours. On average, the TV was on for about five additional hours on a common day.
After accounting for factors（因素）such as living in a violent neighborhood, scientists also found watching TV was strongly connected to behavior such as hitting others, having angry moods, being disobedient（不服从的）, and screaming a lot.
The researchers thought that children may see violence on TV, and spend less time on positive development tasks such as reading or playing.
The American Academy of Paediatrics suggests no TV at all for children at two and younger, and two hours a day or less for older kids.
what is the main idea of the passage?

A．Children should choose positive programs.

B．Children should keep away from TV.

C．Watching TV can make children violent.

D．Parents should watch less TV.

what do we know from Paragraph 2?

A．Children can watch good programs.

B．Children will be affected as long as the TV is on.

C．It’s OK that the TV is on if children don’t watch it.

D．Children’s troublemaking behavior is mainly caused by watching TV.

what can be learned about the study between 2005~2008 from the passage?

A．The TV was on for about three hours.

B．The women studied have different jobs.

C．The study included men and women.

D．Most women allowed their child to watch TV.

Children who spend much time watching TV will ________.

A．not be hit by others

B．be influenced by others

C．become angry easily

D．know more about the neighborhood