our teacher set us such a difficult maths problem we couldn't workd outA.that B.as C.which D.even
问题描述：
our teacher set us such a difficult maths problem we couldn't workd out
A.that B.as C.which D.even
答
横线在哪里？
答
A. that
答
B as
因为C、D可以先排除,在A、B中选,如果选A,那是such...that的结构,that后应接完整的句子,而在这里显然是定语从句,应用as,后面的修饰前面的.