Those math problems were so difficult that___students worked them out
问题描述：
Those math problems were so difficult that___students worked them out
A.few B.a few C.little D.a little
答
选择A.so.that.如此..以致于.,句子的意思是,这些数学题是如此的难,以致于几乎没有一些学生可以做出来."students"是复数,且可数,所以排除C.D(little,a little是修饰不可数名词)B.a few表示一些,与句子意思不是最恰当...