依照国际牙科联合会系统记录牙位的方法,左侧下颌第二前磨牙应该记录为()。
A.15
B.2
C.35
D.45
E.75
参考答案:C
Could you please _____ the window? I feel a little cold. [ ]
A. not to open
B. not open
C. not to close
D. not close
The air pollution is very serious,we should take___________to stop it.
A.some advice
B.some measures
C.some relations
D.some effect