通常情况下, X线显示牙槽嵴顶距釉牙 骨质界的距离为
A.1mm
B.2mm
C.2mm以内
D.3mm
E.3mm以内
参考答案:C
Novak Djokovic won the 2012 Australia Open, ____ Rafael Nadal on January 29, 2012, after a
hard match. [ ]
A. beat
B. was beaten
C. beaten
D. beating
氯化消毒时水中细菌、有机物和还原性物质所消耗的氯的量为()
A.加氯量
B.有效氯
C.需氯量
D.余氯量
E.以上都不是