单项选择题
A.10°-20° B.20°-30° C.30°-40° D.40°-50° E.60°-85°
A.55°-95° B.70°-100° C.60°-85° D.60°-95° E.30°-45°
A.气管分杈部 B.气管分杈部上壁 C.气管分杈部下壁 D.气管分杈部右壁 E.泛指气管分杈部