She _____(can)skate when she was only four.
问题描述:
She _____(can)skate when she was only four.
答
could;原因:后面when she was only four可以知道用过去式
答
could when后从句为过去完成时,所以主句谓语动词用过去分词(主过从过)
答
could 用can 的过去式