根据开采水平数目,井田开拓方式分为单水平开拓和_______开拓。
查看答案
在几个平行剖切面的剖视图中,不应画出剖切面转折处的投影。
输气温度越低则输气能力越大。The lower the conveying temperature, the greater the conveying capacity.
管道当量粗糙度考虑了管道形状损失的影响,一般比绝对粗糙度大2~11%。The equivalent roughness of pipeline takes into account the influence of pipeline shape loss, which is generally 2~11% higher than the absolute roughness.