—May I speak to your manager Mr.Williams at five o’clock tonight? —I’m sorry. Mr. Williams

问题补充：

—May I speak to your manager Mr.Williams at five o’clock tonight?

—I’m sorry. Mr. Williams to a conference long before then.

A. will have gone

B. had gone

C. would have gone

D. has gone

答案：

(答案→)A. will have gone

B. had gone

C. would have gone

D. has gone

解析：考查时态。根据句中的时间状语at five o’clock tonight可知是将来发生的动作，再根据long before than可知用将来完成时。句意：——今晚五点钟我可以与你经理威廉姆斯先生谈谈吗？——对不起。他那时就早已经去开会了。故A正确。