下列哪些是保证电焊设备安全使用的技术数据（）。
A、输入电压
B、额定电流
C、空载电压
D、额定暂载率
参考答案：B, C, D
—Have you noticed the _____ fish there? How long have they _____?
—They _____ several days ago. [ ]
A. dead, been dead, died
B. dying, died, died
C. death, been dead, died
( )是指在质量方面指挥和控制组织的协调活动。
A．质量策划 B．质量控制 C．质量保证 D．质量管理
