停泵时易发生水锤的原因是()
A、单管向高处送水
B、水泵总扬程大
C、输水管道内流速过大
D、输水管道过长易地形变化
E、自动化泵站阀门关闭太快
参考答案:A, B, C, D, E
大于0.3而小于0.6的小数有无数个.______.(判断对错)
If your prices are favorable, we would like to order 1,000 cases____ you.
A. to
B. with
C. for
D. on