答案：C

题目分析：句意：--你将接受提供的这项工作吗？--如果我再年轻5岁，我就接受它。这里是虚拟语气从第一句来看，这里应是对现在的虚拟，从句用过去式，主句用would have done，故选C。

点评：本题难度适中。虚拟语气是高中阶段的重要语法项目，需要考生牢记各种情况的虚拟语气的谓语动词的形式，并要有分析理解语境的能力。

即学即练：You are late.If you ________ a little minutes earlier, you ________ him.

A. came; would meet       B. had come; would have met

C. came; would have met   D. were to come; would meet

解析：B。句意：由句意可知“没能遇到他”,表示对过去事实的虚拟，主句用would/could/should/might+过去分词，从句用过去完成时，故选B。