【题目】 _____ underground for 2 years, David says the worst thing is not the danger but the darkness.
A. Working B. Having worked
C. To have worked D. Worked
在线课程【答案】A
【解析】
试题分析：考查非谓语动词。这里动词变为非谓语动词，表伴随状语，用于修饰主语David,同时work和主语之间构成主动关系，句意为：David在地下工作了两年之后说最糟糕的事情不是危险而是黑暗的孤寂，故选A。