航海英語液化氣體與IGC規(guī)則單項選擇題每日一練(2019.08.01)

來源：考試資料網(wǎng)

1 The vapor pressure of a gas is the pressure necessary to keep it in a(n)（）.

2 The weight of liquefied petroleum gas vapors as compared to air is（）.

3 Combustible gas indicators operate by drawing an air sample into the instrument（）.

4 After the initial cleaning of flue gas in an inert gas system the gas is passed through what device for final cleaning?（）.

5 According to the regulations，normally，manholes in LFG tanks are located（）.