在化工装置中对风机、水泵等能耗大的设备采用()技术节能降耗效果最好。
A、变频调速
B、双速电机
C、液力耦合
D、多级减速机
参考答案:A
You to like the subject after you it for some time.
A.will get; have studied
B.will get; will study
C.got; have studied
D.get; will study
石英砂岩变质后常变为()。
A.板岩
B.石英岩
C.片岩
D.大理岩