The old man abroad for 20 years is on the way back to his mother land.A. to workB. worki

问题补充：

The old man, abroad for 20 years, is on the way back to his mother land.

A. to work

B. working

C. having worked

D. to have worked

答案：

A. to work

B. working

(答案→)C. having worked

D. to have worked

解析：这题考查现在分词的完成时做状语，表示该动作发生在谓语动词的动作之前。to work 将来 /主动，从后面的句子：他在回来的路上，很明显这里已经在国外工作了了。working 表示该动作和谓语动词的动作同时发生或者在它的后面发生。所以选D having worked

考点:考查现在分词的完成时做状语