分类：教育/科学-升学入学-高考
问题：难题Susandecidednottoworkontheprog 
Susan decid not to work on the program at home because she didn't want her parents to know what she _______                                          A. was doing   B.had done
回答：A. was doing

what she was doing - 正在做什么
what she had done - 已经做了什么

susan 的工作还没有做, 但是他不象在家做, 因为她不象让父母知道他在做什么. 所以用A. was doing