题目内容：

Jack couldn't swim across the river.改同意句为Jack wasn't( )( )swim across the river.

优质解答

填able to
Jack couldn't swim across the river=Jack wasn't【able to】swim across the river.
句子翻译是：杰克不能游过那条河
can=be able to（能,能够）
swim across the river：游过那条河