施行口对口人工呼吸时，操作者深吸气后用力吹气时，吹出气中氧浓度是（）。
A.8%
B.5%
C.12%
D.16%
E.20%
参考答案：D
In spite of all has been said，quite a lot of people are still uncertain about the prices of housing in China．
A．that
B．what
C．which
D．as
位于面颊部，耳垂前0.5～1寸处的腧穴是（）
A.听宫
B.颧髎
C.牵正
D.下关
E.颊车
