Now our school is four times it was twenty years ago.A. whenB. whichC. thatD. what

问题补充：

Now our school is four times it was twenty years ago.

A. when

B. which

C. that

D. what

答案：

A. when

B. which

C. that

(答案→)D. what

解析：考察倍数表达。实际上也是一个名词性从句的表达法。What引导起这个从句，并在句中作was的表语。句意：现在我们的学习是前的4倍大。