用括号内所给的单词的正确形式填空 ____ you ever ___(swim) in the sea?---No,never.

问题描述:

用括号内所给的单词的正确形式填空 ____ you ever ___(swim) in the sea?---No,never.

Have ,swum
swim 是不规则动词,其过去式是swam ,过去分词是SWUM,而现在完成时的结构是have/ has +过去分词.