Most of the big hotels in Shanghai were full last week, but finally we find a room in a small one.
A. ought to
B. could
C. were able to
D. might
网友回答
A. ought to
B. could
(答案→)C. were able to
D. might
解析：句意，上周，上海的大多数大的宾馆都满了，但是最后，我们找了一间小的。表示过去通过努力终于做成了某事要用be able to，而不能用can，又因为是发生在过去的事情，故用一般过去时。