—I’m not good at basketball,you know.

—_______ We’re playing for fun.Just try and you’ll see you can do it.

A．Well, it depends.

B．Take your time.

C．Come on.

D．That’s OK.

主肺动脉窗层面不包括哪一解剖结构（）

A.降主动脉

B.气管

C.上腔静脉

D.奇静脉弓通常也位于此层面

E.头臂静脉