That 10-year-old boy______(can swim) at the age of 6.正确形式填空

问题描述:

That 10-year-old boy______(can swim) at the age of 6.正确形式填空

could swim
那个10岁的男孩6岁时就会游泳了.
按照题意,是过去时.
can变为 could