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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
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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
´ËÌâµÄʱ¼ä²ÎÕÕµãÊÇbefore I joined them,£¬ËùÒÔµÚÒ»¸ö¿ÕÓ¦¸ÃÓùýÈ¥Íê³É½øÐÐʱ£¬µÚ¶þ¸ö¿Õ¸ù¾Ýʱ¼änowÓÃÏÖÔÚ½øÐÐʱ¡£