It is so difficult a question none of the kids could work it out.A. asB. that C. whichD. X

问题补充：

It is so difficult a question none of the kids could work it out.

A. as

B. that

C. which

D. X

答案：

A. as

(答案→)B. that

C. which

D. X

解析：考查代词。本题考查so … that …引导的目的状语从句。句意：问题如此的难以至于没有孩子能做出来。