The project alongside with the experiment we had once devoted so much time perfectly.A. t

The project alongside with the experiment we had once devoted so much time perfectly.
A. to work out
B. to working out
C. to worked out
D. has worked out

A. to work outB. to working out (答案→)C. to worked out D. has worked out解析：本题中含有一个定语从句we had once devoted so much time to，这个定语从句修饰先行词the experiment，定语从句中有一个固定搭配devote some time to…花时间在…之上；横线首先要填to，然后再接谓语动词work out。另外定语从句中使用了过去完成时had devoted，说明后面主句使用的是过去的时态。句义：这项工程和我们已经花了很多时间做的实验结果非常完美。故C正确。

我明天再问问老师，叫他解释下这个问题