Too much screen time is bad for kids. Children who watch TV or play computer games for 2 hours or more a day are more likely to have poor (67) , behave badly and have difficulties (68) to other people—even if they are (69) active. Previous research has suggested that young children who use a lot of screen-based entertainment (70) developing difficulties with communication and concentration, as well as other (71) problems and obesity (肥胖). However, it has not been clear (72) these effects are caused by the (73) of physical exercise, long periods sitting (74) or by gaming and TV themselves. Children who watched TV for an (75) of 2 hours or more per day were 61 per cent more likely to have emotional, (76) and concentration problems, (77) using a standard test of children’s psychological well-being. The (78) figure for 2 hours or more of computer-based entertainment— (79) computer games—was 59 per cent. Exercise didn’t help much. The accelerometers(加速计) (80) that even if children did an hour or more of exercise a day, and the exercise was probably (81) enough to make them (82) of breath, those who also watched TV or played on their computers for at least 2 hours daily were still 54 per cent and 48 per cent more likely, (83) , to have psychological problems. The American Academy of Pediatrics(儿科) (84) that children above the age of 2 should watch (85) more than 2 hours of screen-based (86) per day.