Have you heard         news that he is ranked ________first in the competition?

A．a; /

B．/; the

C．the; the

D．the; /

下列关于肺动脉走行的描述哪些正确（）

A.其走行异常是判断右心增大的重要依据

B.肺动脉主干自前下向后上走行

C.上腔静脉后方为右肺动脉干

D.其下方为主动脉弓

E.与右心室相连