How glad the old man was ___his son after so many years.

题目

How glad the old man was ___his son after so many years.
A.seen B.see C.seeing D.to see并说明理由谢谢

答案

选D
可以转化为陈述句
The man was so glad to see his son after so many years.
按成份来解释就是
to see 作为前面一部份的表语