A.1/2 B.1/3 C.1/4 D.1/5 E.1/6
A.上腔靜脈 B.降主動(dòng)脈 C.奇靜脈 D.胃底 E.左主支氣管
A.40%~60% B.50%~70% C.20%~30% D.90%~100% E.10%~20%