解析: 【解析题】共鸣腔有分类,根据共鸣腔的声音和声区的特点,主要分为:胸腔共鸣,口咽腔共鸣,头腔共… 继续阅读 In many cases, in unstressed syllables, letters like a, o, u are weakened into a schwa /?/. Pick out the one which does not conform to the rule.