问题
选择题
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
答案
C
考查动词的时态。因为主语的工作当时尚未完成，又处于过去的时间背景当中，所以采用过去进行时态。
