I used to swim.(改为否定句） I＿ ＿ ＿swim.I＿ ＿ ＿swim.

I used to swim.(改为否定句） I＿ ＿ ＿swim.I＿ ＿ ＿swim. I used to swim.的 to swim 是什么语? I can swim.同义句：I ( ) ( ) ( ) swim I'm not sure he can swim 改为否定句 i can not swim.变为否定句 To learn to swim is difficult for me(改为同义句） ＿＿difficult for She likes to swim in the sea.改为否定句 I live on the twelfth flo I used to swim in the river near my home（改为一般疑问句）还有一些 I prefer (boat) to (swim) i learn how to swim I am going to swim this afternoon.（否定句和一般疑问句） I think chickens can swim.改为否定句：I ( )think chicken can not s