Is it on September 1st students come back to school every year ?A. whenB. thatC. whichD.

问题补充：

Is it on September 1st students come back to school every year ?

A. when

B. that

C. which

D. who

答案：

A. when

(答案→)B. that

C. which

D. who

解析：

这题考查强调句：强调句一般问句的结构是：Is it 强调部分+that…？强调的是时间状语：on September 1st句意是：学生每年回去上学是在九月一号吗？选B。