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

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 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：句意：-----我可以在今天下午五点跟你们经理Mr. Williams通话嘛？--很抱歉，今晚5点钟前，他将已经去开会啦。和before then连用，用将来完成时。选A。