the swimming pool is fifty metres long.对fifty metres 划线提问划线部分是fifty metres long时呢？

The boy is swimming at the pool.为什么是at the pool?用in the pool There is a 20-metre-long swimming pool there.The swimming pool is ()()() The swimming pool is on the playground.有错吗? Jenny is swimming in the swimming pool 对划线部分提问 swimming划线 The dog is swimming at the pool ,对at the pool提问 She is swimming at the pool改为一般疑问句 girl,in,who,the,pool,is,swimming连词成句 连词成句:girl,in,who,the,pool,is,swimming --------- Mike like swimming at the pool?是is 还是are Everybody is in the swimming pool改为否定句 what about------（swim）in the pool?look,she is swimming in the pool Les is swim in the pool.同意句 — — swimming in the pool?— —swim in the pool? There is also a 50-metre-long swimming pool 同义句=The swimming pool is ( ) ( ）（） there is a swimming pool near school 还是 there is a swimming pool near the school?我认为是后者 swimming (at)还是(in) the swimming pool look.the man with his friends ( )at the pool.括号里应填：is swimming或are swimming She is swimming（at the pool)对括号句子提问 ___ ___she swimming? jim with his friends ()in the pool now ,这里为什么填is swimming而不是are swimming