问题补充:
By the end of last week, we a satisfactory solution to the problem.
A. have found
B. will be finding
C. had found
D. found
答案:
A. have found
B. will be finding
(答案→)C. had found
D. found
解析:考查时态。By到….为止,与完成时连用;句中the end of last week又是指过去的时间,所以使用过去完成时。句意:到上个星期结束的时候,我们已经找到了这个问题的令人满意的解决方法。