单选题 ______ are produced by constricting or obstructing the vocal tract at some place to divert, impede, or completely shut off the flow of air in the oral cavity.
【正确答案】 A
【答案解析】解析：考查辅音的发音方式。声道的某些部位受到压缩或阻碍后，使得气流在口腔里转向、受阻或完全被阻挡，由此产生辅音。