无牙颌牙槽嵴终身持续吸收，一般每年为（）
A.0.5mm
B.0.8mm
C.1mm
D.1.2mm
E.1.5mm
参考答案：A
—____ he in the dancing or singing class?
—Dancing class. He likes dancing very much. [ ]
A. Does
B. Is
C. Which
D. Will
在进行风量计算时，理论空气量通常采用（）Nm3/kg。
A、1.0以上
B、0.01
C、8.89
D、0.575
