有时前牙牙冠的舌面有钩由牙勒质延伸到牙骨质的牙是（）。
A.3
B.3
C.1
D.2
参考答案：D
We were lucky enough， for no sooner _____ home _____ it rained.
A．we returned， and
B．we had returned， when
C．did we return， when
D．had we returned， than
设备购置费中应包括( )。
A．设备采购与储运费用
B．工器具购置费
C．生产家具购置费
D．生活家具购置费
