单项选择题
A．superior part of duodenum B．descending part of duodenum C．horizontal part of duodenum D．ascending part of duodenum E．duodenojejunal flexure
A．supplies most of the interventricular septum B．divides into anterior interventricular branch and circumflex branch C．runs between the pulmonary trunk and the left auricle D．supplies posterior 1/3 of interventricular septum, E．supplies lesser portion of anterior wall of right ventricle
A．trachea B．superior vena cava C．brachiocephalic v. D．vagus n. E．greater splanchnic n.