曾为水井供水的蓄水层正式宣告干涸了。The aquifer which had once fed the wells was pronounced dry.地下蓄水层是一些有水的岩石层,如沙岩和白垩岩.An aquifer is a water - bearing rock stratum such as sandstone and chalk.就蓄水目的说, 这些地下水库比地表水库有很多优点.For storage purposes,...
提出胶管组合件的设计参数和要点.The designing parameters and the main points are offered.NBR胶板, 胶条,胶管, 胶棒. 硅胶板,条, 管.NBR sheet Plastic strips, hoses, Jiaobang . Silica gel plates, of the tube.将放喷和压井胶管与伸缩节连通.Connect the choke and kill lin...