题目内容：

When I was walking across the square,I saw a plane_______over my head.
When I was walking across the square,I saw a plane_____ over my head.A) flies B) fly C) flew D) flown

优质解答

只有选B,see sb/sth doing/do sth,看到……正在做或者全过程
这里没有flying的选项,只有选fly,用原形表示“看到某事的全过程”