下列说法正确的是（　　）

A．正数和负数互为相反数

B．任何有理数都有相反数

C．任何有理数都有倒数

D．a是有理数，-a是负有理数

-----You were brave enough to raise objections at the meeting.　　

-----Well, now I regret ____that.

A．to do

B．to be doing

C．to have done

D．having done