长管的水力计算公式中,对于层流流态,系数β常数为().
A. 1
B. 0.0246
C. 4.15
D. 5
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当事人对人民调解工作不满意或不配合,是否表示当事人已经拒绝调解,什么情况下人民调解员可以中止调解?
What is the substance called which can readily be converted from a liquid into a vapor, and also from a vapor into liquid with a reasonably narrow range of pressure?()
A. Refrigerator
B. Refrigerant
Cooling medium
D. Brine
ARQ通信中,无以下信号.()
A. 呼叫块
B. 结束块
C. 信息块
D. CS块