Theyon the program for almost one week before I joined them, and now we on it as no good r

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

(答案→)A. had been working; are still workingB. had worked; were still workingC. have been working; have workedD. have worked; are still working解析：试题分析:句意：我在加入他们之前，他们从事这个项目已经有几乎一周的时间了，现在我们仍然在做这个项目，因为到目前为止还没有好的结果出来。根据时间状语从句before I joined them可以判断主句应该用过去完成时，而后句中的now决定了第二个空的时态是现在时态，故答案选A。

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