she works hard at it为什么用at?用in for to?为什么不行?

she works hard at it为什么用at?用in for to?为什么不行? She always works hard at it,though there is much troubleShe always works hard at it,but there is much trouble She good at ping-pong at PE.还是She is good at ping-pong at PE.She works hard at chinese.还是She is works hard at chinese. she works hard at English的同义句谢谢了, Neither you nor she works hard at English. school,hard,at,works,she该怎么拼 school,hard,at,works,she该怎么拼 she works hard,but she don’t good at mathsshe works hard,but she【】 good at maths A.don’t B.isn’t C.aren’t She works hard 对 hard 提问 Sally has Chinese,English,math and ____subjects at school.She works hard. lucy is the b___ student in our class she always works hard at her lessons She works very hard the day.A.at B.on C.in D.of maria works hard at chinese .so she has made great p_____ in chinese .这个空写啥? He wants to i_______ his English,so he works hard at it she is always works hard.中文是 she works hard .(同义句转换) She works very hard.改同义句 she works hard改为复数形式