问题

The book was written in 1946, ____ the education system has witnessed great changes.

A:when
B:during which
C:since then
D:since when

正确答案是：

同类题型

下列各句中，表达得体的一句是（）

een valley, we thought we had reached the land

____ a basketball player ，he wants to be a person ____ Yao Ming is popular.

____ a new building _____ in your school last year

Don’t lose _____ in computer games, boys.