污水缓冲罐（T-D01A/B）的操作压力为（）。 ["常压","低压","中压","高压"]
If the vessel does not arrive by the canceling date，and the Charterer（）expenses，these expenses can be claimed by him from the Shipowner where they are in the reasonable contemplation of the parties. ["occurs","incurs","discus","recur"]
留矿采矿法采空区靠暂留矿石支撑。
简述锚头鱼蚤病的防治方法。
It is possible to mount a double suction centrifugal pump impeller with the vanes facing in the wrong directionThis would cause the pump （）. ["head capacity to improve","discharge to be reversed","efficiency to decrease","slippage to decrease"]
试述现浇钢筋混凝土楼梯根据结构形式的不同如何分类？
