The weather behind a cold front is dominated by

mixed air mass

cold air mass

warm air mass

Cold front is dominated by a "cold air mass".

Explanation:

Cold air mass moves to replace a warm air mass giving rise to a cold front. The different air masses do not mix as they have different temperatures and densities. This is because the warm air has less density than cold air. Clouds are the best example as the moisture in the air condenses as the warm air rises and cools. These are the masses of cool and condensed air. If we pass through a cold front, we definitely feel the cool air and dryness.  

Amath expression is a collection of one or more terms, which are separated by the signs ( + , - , x , / ).example :   8+b8+b  or  a−3a−3in algebra, an equation is a mathematical statement with two expressions where, each expression is separated by an equal (=) sign. variables can be present on both the sides of the equality (=) sign and we use letters to denote such variables.example 1:   x=4+2x=4+2  , [here, we can observe that the variable is present only on one side of the equation].example 2:   2x+3=x+42x+3=x+4  , [here, we can observe that the variables are present on both side of the equation].

The answer is d if you are on edgenuity.