溴化锂吸收式制冷机中设置抽气装置是为了( )。
A．抽除不凝性气体 B．抽除水蒸气C．防止结晶 D．提高系统真空度
参考答案：A
通过高电压试验的手段，掌握设备绝缘状况的试验称为（）。
A.工频耐压试验
B.绝缘试验
C.交接试验
D.预防性试验
35. The manager came over and asked the customer how ___________.
A．did the quarrel come about
B．does the quarrel come about
C．the quarrel has come about
D．the quarrel had come about
