美国医学物理学家学会(AAPM)规定加速器楔形板、限光筒位置精度为()
A.1mm
B.2mm
C.3mm
D.4mm
E.5mm
参考答案:B
I heard_____ voice that had been shouted to me as a child.
A.every
B.such
C.any
D.one
检修设备和可能来电侧的断路器(开关)、隔离开关(刀闸)应断开控制电源和合闸电源,应确保不会误送电。