some students are not aware of is difficult life can be if they are not devoted to stud

some students are not aware of is difficult life can be if they are not devoted to study.
A. That; how
B. Which; what
C. What; what
D. What; how

A. That; howB. Which; whatC. What; what(答案→)D. What; how解析：D　句意：一些学生没有意识到的是如果他们不专心学习，生活可能会是多么的难。“ some students are not aware of”为主语从句，该从句缺少宾语，表示“事物”且语境中并无选择含义，故用what引导；“ difficult life can be”为表语从句，其中life为主语，设空处后为形容词，故用how引导。本题易误选C项，考生误以为第二空后的difficult life为名词，故用what引导，但是如果那样的话“ difficult life can be”便没了主语，也就不能成为一个从句，第二空如果填what，应改为：what difficult life it can be。

这下我知道了