[单选] Prior to backloading portable tanks or drums onto an offshore supply vessel，check that each tank is（）.

储蓄国债（电子式）在认购三个月以后提兑可以收到国债利息。 配电网线路故障后，调控员通知巡线时有哪些规定？ The follow-up gear on an electro-hydraulic steering gear（） relieves excessive fluid pressure。 takes the pump off stroke when the desired rudder angle is attained。 synchronizes wheel position with the rudder position。 returns the rudder to midposition when the wheel is released。 影响微管装配的因素有（） 秋水仙素。 紫杉醇。 Ca²⁺。 重水。 简述络筒的工艺参数。 Prior to backloading portable tanks or drums onto an offshore supply vessel，check that each tank is（）.