Susan decided not to work on the program at home because she didn’t want her parents to know what she     .

A．has done

B．had done

C．was doing

D．is doing

[听力原文]男：你有什么问题吗？女：您今天在课上讲的内容，我不太明白。问：他们是什么关系？（）

A．同学 

B．同事 

C．老师和学生 

D．服务员和顾客