單項選擇題Vapor given off by a flammable liquid will burn when ignited provided（）

A.the vapor and air mixture is too rich
B.it is mixed with certain proportions of air
C.the vapor is too little compared to the air
D.it is of heavy toxicity


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1.單項選擇題Fixed piping leads from the（）to various areas of the compartment to be flooded.

A.manifold
B.remote pull box
C.discharge nozzle
D.machinery space

3.單項選擇題Which of following physical abilities is not required as to the routine movement around a vessel?（）

A.Maintain balance and move with agility
B.Climb up and down vertical ladders and stairways
C.Open and close watertight doors
D.Take part in vessel evacuation procedures

5.單項選擇題On a weather map,a large letter “h” means（）

A.a high pressure area with cool, dry air and fair weather
B.a high pressure area with warm, moist air and inclement weather
C.horse latitudes, with rough seas and strong winds
D.a heavy squall line near the “H”