By the end of last week we a satisfactory solution to the problem.A. have foundB. will b

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。