Great changes have taken place in that school. It is no longer it was 20 years ago it

问题补充：

Great changes have taken place in that school. It is no longer it was 20 years ago, it was so poorly equipped.

A. that; which

B. what; when

C. what; which

D. which; that

答案：

A. that; which

(答案→)B. what; when

C. what; which

D. which; that

解析：考查表语从句和定语从句。本题第一空是what引导的表语从句，what在句中充当系动词was后面的表语。第二空是一个定语从句，定语从句的句子结构很完整，就使用关系副词when引导这个定语从句。句意：在那所学校里已经发生了巨大的变化，它已经不再是前的那所学校了，在那时它的设备很差。故B正确。