the program they have to stay there for another two weeks.A. Not completingB. Not comple

问题补充：

the program, they have to stay there for another two weeks.

A. Not completing

B. Not completed

C. Not having completed

D. Having not completed

答案：

A. Not completing

B. Not completed

(答案→)C. Not having completed

D. Having not completed

解析：句意是：没有完成计划，他们只好再呆两星期。因为是先没有完成计划，才要呆在那里。因为是先没有完成计划，然后才又待了两个星期，用现在分词的完成式，否定not放在having的前面。选C。