The polar air masses are air masses that form on the high latitudes, in the polar regions. The tropical air masses are air masses that form on the low latitudes, around the equator.
The polar air masses are cold air masses. They are also dry, very dense, and have much higher air pressure. The tropical air masses are warm air masses. Depending have they formed over land or over sea, they can be either dry or moist, and they have low air pressure as they are much less dense.
A typical polar air mass brings in cold and dry weather, while the tropical air mass brings in warm weather, with either lot of precipitation, or being very dry.
The polar air masses are moving from the high latitudes toward the lower latitudes, while the tropical air masses are moving from the lower latitudes toward the higher latitudes.
Ocean trenches are long, narrow depressions on the seafloor.
CH4 + 02 → H20 + CO2
balance equation
CH4 + 2O2 → 2H2O + CO2
4 ÷ ( 12 + 4 ) = 0.25 mol
1 : 2
no mole of H2O = 0.25 × 2 = 0.5 mol
mass of H2O = 0.5 × ( 2 + 16 ) = 9g
I think the correct answer from the choices listed above is option D. The type of dispersal that occurs due to global trade would be jump. <span>Jump-dispersal is the movement of individual organisms across great distances, followed by the successful establishment of a population.</span>