the task they have to stay there for another two weeks.A. Not completingB. Not complete

问题补充：

the task , 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：考查现在分词的完成式做状语，因为他们是先没有完成任务，然后不得不在这儿再待两个星期。表示从句的动作先于主句的动作，要用现在分词的完成式，否定式是：not having done。选C。