上下颌双侧后牙缺失,排牙时应以哪个牙的咬合关系位置做标准?()
A.第一前磨牙
B.第二前磨牙
C.第一磨牙
D.第二磨牙
E.第三磨牙
参考答案:C
I still remember how many years ago_______ I last met her in the countryside.
A.when it was
B.was it that
C.when was it
D.it was that