问题补充：
— That must have been a long trip.
— Yeah, it us a whole week to get there.
A. takes
B. had taken
C. took
D. was taking
答案：
A. takes
B. had taken
(答案→)C. took
D. was taking
解析：考查时态。根据题中用must have done可知知道是对过去事情的推测，故用一般过去时。句意：——那一定是个很长的旅行。——嗯，花了我们一个周到达那儿。故C正确。
