1. They ______ on the program for almost one week before I joined them, and now we _____on it as no good results have come out so far.
A. had been working; are still working B. had worked; were still working
C. have been working; have worked D. have worked; are still working
解析：此题的时间参照点是before I joined them,，所以第一个空应该用过去完成进行时，第二个空根据时间now用现在进行时。
答案：A
