He added that they（ ）day and night for nearly a week to get the

He added that they（ ）day and night for nearly a week to get the car going again.
A、had been working
B、have worked
C、have been working
D、worked
【正确答案】：A
【题目解析】：由句意可知时间发生在过去的过去，所以用若去完成时态，但又由于后有for nearly a week时间段，所以可知在一段时间内的持续性动作。所以用had been working