请益今年邮政考试的考题^^
Catherine was________that she was always on top of her class back in her schoo
l days.
1 so diligent a student
2 a so diligent student
3 such a diligent student
4 a such diligent student
公布答案为1
我想请问为什么3不行呢？
such后面可接 a(an) +形容词 +单数名词不是吗？
麻烦给予纠正指教
谢谢！！