Some scientists believe that it won’t be long robots are widely used in all walks of life．
A. since
B. after
C. before
D. until
网友回答
A. since
B. after
(答案→)C. before
D. until
解析：考查特殊句型。It be 一段时间 before从句;表示一段时间以后某事才发生。句意：一些科学家认为不就以后机器人就将在各个领域广发被使用。故C正确。