she couldn’t understand was fewer and fewer students showed interest in her lessons.A. W

问题补充：

she couldn’t understand was fewer and fewer students showed interest in her lessons.

A. What；why

B. That；what

C. What；because

D. Why；that

答案：

(答案→)A. What；why

B. That；what

C. What；because

D. Why；that

解析：考查名词性从句。what she couldn’t understand是主语从句，what引导这个主语从句并在句中作宾语。后面是一个表语从句，句子结构很完整所以应该使用连接副词，再从句意考虑，使用why。句意：她不能理解的是为什么越来越少的学生对她的课感兴趣。