在心底短轴不能显示冠脉的哪一支（）.
A.左主干
B.左前降支
C.右后降支
D.右主干
E.左旋支
参考答案：C
--- How do you find your new classmates?
----Most of them are kind, but _______ is so good to me as Bruce.
A．none
B．no one
C．everyone
D．someone
一般照明的电源优先选用（）V。
A、220
B、380
C、36
