the boy is swimming ___the river 为什么填across而不是in

the boy and the girl is swimming now改错 The boy is swimming across the river.变为被动语态 There is a boy ___ in the riverA swimming B swim C swims D is swimming The boy is swimming in the water.对swimming划线部分提问 The boy is good at swimming The boy（ ）（ ）.同义句 The boy is swimming at the pool.为什么是at the pool?用in the pool look,the little boy ____in the lake.A.is swiming B.swims C.is swimming Is the boy ______ in the river?He's__________in the swimming pool. A:Is the boy ( ) in the river?B:No,he( ).He's( )in the swimming pool. the boy is like a fish swimming in the river.其中有固定搭配吗 现在进行时问题what are you doing?what is the boy swimming?为什么swimming后面不加doing? 如何将Do you know the boy who is swimming over there?转换为Do you know the boy( the boy is swimming ___the river 为什么填across而不是in I know that boy .He is swimming in the lake.改为定语从句 The boy swimming in the river is my friend Dave.(对swimming in the river 提问）_________boy is _________friend Dave? The water in the pool is a little_____ .but the boy is swimming in it.Help!单词的格式：_oo_ The boy likes swimming in summer（改为一般疑问句）( )the boy ( )swimming in summer? The boy is swimming.His father is ()him.A.looking B.seeing C.watching D.look at