They didn't leave the airport until they saw the plane_____(take off) and fly into the clouds.
问题描述：
They didn't leave the airport until they saw the plane_____(take off) and fly into the clouds.
填什么?原因.
为什么不是taking off?
答
take off
see sb do sth
saw 在这里要接无to 不定式作宾补,与后面fly into the clouds形式一致为什么要和后面的一致？谢谢因为take off 和fly into the clouds属平行结构， 两个并列的无to 不定式作saw 的宾补。其结构为：see sb do A and do B