问题补充：
They on the program for almost one week before I joined them, and now we it as no good results have come out.
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
答案：
(答案→)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：考查时态。根据before I joined them和for almost one week可知第一空是过去的过去，使用过去完成进行是时；根据now和句意可知第二空使用现在进行时。句意：在我参加他们之前他们就已经做了几乎一个星期了。现在我们仍然在努力工作，因为好的结果还没有出来。
