题目内容：

It is _question that i can't work it out.A.a so difficult B.so a difficult C.so difficult a 请帮我

优质解答

选C 固定用法 so + adj.such + a(n) + n.
so + adj.+ a(n) + n.such + n.(pl.)
so + adj.+ n.(pl.) such +n.(pl.)
so + adj.+ n.[不可数] such +n.[不可数]