The ambulance was just arriving, for a worker, who ______ the window on the second floor, fell off the window.
A.had been repairing
B.was repairing
C.has been repairing
D.would be repairing
网友回答
A解析考查时态。由题干可知救护车的到来用了过去时，这位工人修窗户是在救护车到来之前，那么应该使用过去完成时，为了强调动作一直在发生，所以又用了过去完成进行时。