单项选择题 Protective clothing must be worn while sampling hazardous cargo on a tanker，and as a minimum includes（）.

单项选择题 On the all-purpose nozzle，the position of the valve when the handle is all the way forward is（）.

单项选择题 On a vessel carrying grades A，B，C or D cargoes，enclosed spaces where sources of vapor ignition are normally present shall NOT be segregated from cargo tanks by（）.