He was seen () in the reading room an hour ago.

问题描述:

He was seen () in the reading room an hour ago.
A.sit B.sitting C.sat D.to sit
我们老师说选D.可为什么不是B

不是不可以
应该是
he was seen sitting in the reading room an hour ago 就代表有人看见了他”正在“坐下
而he was seen to sit in the reading room an hour ago代表有人看见他坐在图书馆里