下颌处于休息状态时，上下牙弓自然分开成一楔形间隙称（）

A．颌间隙

B．息止隙

C．高度

D．颌间距离

E．垂直距离

— I told you that he would come to see you.

— Actually I had little doubt _____ it was true.

A．whether

B．that

C．since

D．if