some word puzzle in this book are __difficult that___ students can solve them.
问题描述：
some word puzzle in this book are __difficult that___ students can solve them.
A such;free
B such;little
C so;free
D so;little
答
C 应该是 so ,few
so ……形容词 +that 如此……以致于……
students 是可数名词复数,不能用 little 修饰
意思是：这本书里的字谜是如此的难以致于很少有学生能做出来.那such的用法呢such +形容词+名词+that