焊条电弧焊使用设备是电弧焊机，常用的电焊机有（）、（）。
参考答案：弧焊变压器、弧焊整流器
— I think ______ of the materials I listened to at the beginning of the exam ______ easy.
— I think so.
A．three fourths, is
B．third four, are
C．three fourths, are
D．three fourth, are
试述格拉斯哥评分及其意义。
