单项选择题
A.1% B.2% C.3% D.4% E.5%
A.1~2气管环 B.2~4气管环 C.4~5气管环 D.5~6气管环 E.6~7气管环
A.环杓后肌 B.环杓侧肌和杓肌 C.环甲肌 D.甲杓肌 E.杓会厌肌