—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

—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

—May I speak to your manager Mr. Williams at five o’clock tonight?
—I’m sorry, Mr. Williams _____ to a conference before then.

-- May I speak to your manager Mr. Williams at five o’clock tonight?
--I’m sorry. Mr. Williams _______ to a conference long before then.”

— “May I speak to your manager Mr. Williams at five o’clock tonight?”
— “I’m sorry. Mr Williams ________ to a conference by then.”