she couldn’t understand wasmore and more students showed little interest in their lessons

问题补充：

she couldn’t understand wasmore and more students showed little interest in their 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引导起主语从句what she couldn’t understand，在句中understand的宾语。Why more and more students showed little interest in their lessons是 一个表语从句。因为句子很完整，所以使用连接副词why引导。句意：她不能理解的是为什么越来越多的学生对他们的课程没有兴趣。