C

Good computerskills are desirable in today’s digital age，and playing computer games can help children practice those skills—as long as they don’t overdo it．scientists warn．A British study found that thosewho played computer games less than once a week achieved better grades atschool than ones who played them twice a day or more often．The study also found that daily useof social media did not affect school performance．

“It was clear that social media didn’t have any impact．I think that’s more because social media is part of every child’s life．It’s the way they communicate．It’s the waythey keep in touch with their friends，”said Celine McStravick of the National Children’s Bureau Northern Ireland．

Parentsincreasingly complain of having difficulty getting their children away from    computer games．Some even seek help for theirteenagers who they say are addicted to them．The study did not look into addiction，but suggested computer games can cause children to stay up late inthe evenings，making themtired and less able to focus at school the next day．

Mark Starkey，the owner of the Heart of Gamingcomputer game outlet(批发商)in London，said there is also the difference between older games and the newones．

“The ability to make games a lot more bigger，a lot more detailed，a lot more complex is  here now．It's going to hold their attention longer．‘Oh my god，I have to see what happens next’etc．However，the old games challenge more your hand-eye coordination(协调)，your speed，your timing，your reactions，rather than your imagination，”said Starkey．

The gamesindustry has long claimed there is no proven link between games and addiction．But the new study says additionalresearch is needed to establish the effect of computer game- playing onperformance at schoo1．

31．What can we infer from the passage?