— Do you know when Mr Wang            back? 

— Sorry, I don't know. But I'll tell you as soon as he            back. [ ]

A. will come; comes

B. comes; comes

C. comes; will come

D. will come; will come

实施谈判威胁的首要条件是( )

A．权力因素

B．沟通渠道因素

C．可置信性

D．环境因素