It is so difficult a problem that student in this class work it out.A. any can'tB. no

问题补充：

It is so difficult a problem that student in this class work it out.

A. any, can

B. no, can

C. every, can

D. no, can 

答案：

A. any, can

(答案→)B. no, can

C. every, can

D. no, can 

解析：此题很容易误选A，因为从句意上看，选A可将此句理解为“这个问题是如此之难，这个班上任何一个学生都不可能做出来”。但按英语习惯，any(任何一个)作为非肯定词，它只能出现在否定词not之后，而不能在其前，即可说not any,但不说any not。所以正确答案应选B。