压缩机加负荷时必须遵循（）原则
A、先升速再升压
B、先升压再升速
C、升速升压同步进行
D、以上都不对
参考答案：A
生产9.52*0.27*0.16内螺纹铜管所需减径模规格为（）
A.12mm
B.11.56mm
C.12.56mm
D.11mm
I have _______ money than you, but I have_______ friends than you.
A．less, fewer
B．more, more
C．less, more
D．fewer, more
