正常成人右下肺动脉主干直径一般不超过()
A.5mm
B.10mm
C.15mm
D.20mm
E.25mm
参考答案:C
-- Do you want to watch a sports show tonight?
--- ______. I hope to watch the news.
A.Yes, I love watching it .
B.I can’t stand it .
C.I don’t mind it.
D.I hope so.
在狭小空间、船舱、容器和管道内焊接时,为防止触电,脚下垫橡胶板或其他绝缘衬垫、焊工必须( )。
A.穿绝缘鞋
B.穿紧身工作服
C.戴绝缘手套
D.戴好安全帽