This question is so hard that very students can answer it.
A. few
B. little
C. a few
D. a little
网友回答
(答案→)A. few
B. little
C. a few
D. a little
解析：few很少，表示否定含义，修饰可数名词复数；a few几个，表达肯定含义，修饰可数名词复数；little很少，表达否定含义，修饰不可数名词；a little一点，表达肯定含义，修饰不可数名词。句意：这个问题是如此之难，以至于很少有学生能回答。结合语境可知下文表示否定含义，学生们是复数形式，故选A。