问题
选择题
We _______ finish it ahead of time, though it was such a tough task.
A．could
B．would
C．were able to
D．ought to
答案
答案：C
考查情态动词。could 能够，would 会，were able to 成功做成什么事，ought to 应该，句意：我们成功的提前完成了任务，虽然这是一个如此艰难的任务。所以选C。