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 C. ought to
答案
答案：C
句意“虽然这是一项十分艰巨的任务，我们还是提前完成了”，表示经过特殊的努力而完成的努力，应用be able to;could 只表示一般性能力。
【标签】情态动词辨析
