终轧温度主要是通过机架间冷却水和（）速度控制的.
参考答案：轧机
They had kept working for several weeks everything was in order.
A．before
B．after
C．since
D．unless
交流弧焊机变压器一次侧电源线长不应大于（）m。
A.3
B.5
C.30
