单选题 (After) his (graduation) (from) the university, he has (worked) in a famous computer company.
A. After B. graduation C. from D. worked

【正确答案】 A
【答案解析】[解析] 应改为Since。因为后面主句用的是完成时态，常用完成时连用的是since，表示“从那以后”。