辅助主动运动主要适应于肌力几级的患者？（）
A.O级
B.1级
C.2级
D.3级
E.4级
参考答案：C
They are in high spirits.They ___ have been defeated in the game.
A．can
B．can’t
C．may
D．mustn’t
什么是抽出式通风？
