--- How e your father can read books in German?
--- Well, he on a project with some German engineers for 3 years when he was young.
A. worked
B. was working
C. had worked
D. would work
网友回答
(答案→)A. worked
B. was working
C. had worked
D. would work
解析：考查时态。句意：——你父亲怎么能用德语看书？——哦，他在年轻时和一些德国工程师共事过3年。从时间状语when he was young可知主从句动作同时发生，排除答案C和D，根据语境可知，他现在不再和德国工程师共事，所以只是强调过去的一个事实，故使用一般过去时。此题容易根据时间状语for 3 years 误选答案C。