[单选题]关于排痰训练说法正确的是
A.体位引流主要利用重力促进各个肺段内积聚的分泌物排出
B.不同的病变部位可采用相同的引流体位
C.胸部震颤是在深吸气时作颤摩振动
D.胸部叩击时患者需屏气
E.胸部叩击时治疗者手指伸直，以手掌部位拍击引流部位胸壁

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