单项选择题
A.Certificate of Inspection B.loading order C.rules and regulations for tankers D.tankerman's document
The weight of liquefied petroleum gas vapors as compare...
单项选择题The weight of liquefied petroleum gas vapors as compared to air is（）.
A.variable B.the same C.lighter D.heavier
The vapor pressure of a substance（）.A.decreases as temp...
单项选择题The vapor pressure of a substance（）.
A.decreases as temperature increases B.increases with the temperature C.is not affected by temperature D.may increase or decrease as the temperature rises
The vapor pressure of a gas is the pressure necessary t...
单项选择题The vapor pressure of a gas is the pressure necessary to keep it in a(n)（）.
A.soluble state B.solid state C.liquefied state D.inert state
