自己英语好怎么写

　　I was good at sums at school.

　　我上学时擅长算术。

　　He's not very good at arithmetic.

　　他不太擅长算术。

　　You need manual dexterity to be good at video games.

　　玩好电子游戏手要灵巧。

　　My secretary is very good at filtering my calls.

　　我的秘书很会替我推掉不相干的电话。