单项选择题 Hoses used for cargo transfer operations must be tested and inspected at specified intervals by（）.

单项选择题 Each inert gas system gas main must have an automatic shut down valve at the outlet of the gas production plant. This valve must close automatically upon（）.

单项选择题 During loading and discharging operations，in addition to when the cargo tanks have been properly filled，each inert gas system must be capable of maintaining a minimum gas pressure of（）.