He knew that cholera would never be controlled its cause was found.A. tillB. stillC. unti

问题补充：

He knew that cholera would never be controlled its cause was found.

A. till

B. still

C. until

D. kill

答案：

A. till

B. still

(答案→)C. until

D. kill

解析：考查：not/never …until,直到……才， 句意：他知道霍乱将永远不会被控制，直到它的起因被找到。故选C。