Question

名词性从句19.Output is now six times___it was before liberatoin.

A.that
B.which
C.what
D.of which

答案是D，我选的是c
wHY
详细的解释，谢谢了
答案是C,我选的D~~抱歉

Answer 1

可以说six times the amount of what it was before liberation,这用的是倍数+ the +名词 (size/length/width/height...)of...的结构，当然也可以说Output is now six times what it was before liberatoin，此种情况下相当于省略了“名词 (size/length/width/height...)of...”结构，后面直接跟名词性从句，而本句中what it was before liberatoin 就是一个以wh特殊疑问词引导的名词性从句，指的是之前的产出。

类似的句子还有：The production is now double what it was ten years ago. 现在的产量是十年前的两倍。多看几个例子，认真体会这样一种用法，顺便找点语感。

Answer 2

这里是定语从句，现在的output与以前的对比，which指代以前的output,what不能引导

Answer 3

six times of output，which指代output