Tony for the pany as an engineer for two decades. Now he teachesmechanics m Peking University.
A. has worked
B. worked
C. is working
D. had worked
网友回答
A. has worked
(答案→)B. worked
C. is working
D. had worked
解析：考查动词的时态。句义：唐妮在这个公司做工程师做了20 年，现在她在北京大学教力学。前句是说明她的过去的工作经历，后句是说明她现在的工作。所以前句应该用一般过去时，所以B正确。