正常覆为上切牙切缘盖过下切牙唇面的垂直距离（）
A.3mm
B.4mm
C.5mm
D.颈1／3
E.切1／3
参考答案：E
I want ____ the room. Could you please ____ me? [ ]
A. to clean, to help
B. cleaning, helping
C. to clean, help
D. clean, to help
甜菊苷其甜度比蔗糖约大()倍
A.[300]
B.[200]
C.[100]
D.[10]
