A. five of them were rude and badly behaved B. one of them was rude and badly behaved C. one of them was quiet and well behaved 参考答案:B 答案解析:[解析] 文章第一段就告诉读者,车厢里只有一个年轻人不讲礼貌。
第32题: [单项选择]鸭的发声器官是() A. 鸣管 B. 气囊 C. 鸣膜 D. 鸣骨 E. 鸣泡 参考答案:E 答案解析:鸣管是禽类的发音器官,由数个气管环和支气管环以及一块鸣骨组成。鸣骨呈楔形,位于鸣管腔分叉处。在鸣管的内侧、外侧壁覆以两对鸣膜。当禽呼吸时,空气经过鸣膜之间的狭缝,振动鸣膜而发声。公鸭呜管形成膨大的骨质