之前才跟学生提醒不要只用被动主动判断加ving 还是pp 例如She rode thw bike with her hair blowing. 要想到是 Her hair blows. 是主 动语态，不要觉得 头发是被风吹的而写blown 但是! 刚刚有句觉得有疑问 She sings with her hands waving. 后面似乎不能还原成Her hands wave. 因为几乎不会这样说，而是说Someone waves hands. 如此,我要怎么解释如何判断用ving/pp呢? 谢谢!!