The book was written in 1946,_____the education system has w
The book was written in 1946,_____the education system has witnessed great changes.为什么答案是since when,而不是since which?
此句中不缺少主语或宾语,因此缺少状语成分,但不应该是when=since which么?那另一道题:We are just trying to reach a point_____both sides will sit down together and talk.为什么这道题要填where而不是at where啊?