9月1日早上9：10--9:14
I saw Tom get into his car and drive away.
用不带to 的不定式：
We saw them go out.
在被动语态后面要加 to :
They were seen to go out.
我只是看到他正在做某事，并没有看见动作的全过程：
I saw him walking along the street.
有时区别不重要：
I've never seen her dance. I've never seen her dancing.
