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What type of air mass will cause a cold front?

Cold fronts form when a cooler air mass moves into an area of warmer air in the wake of a developing extratropical cyclone.

Explanation:

The warmer air interacts with the cooler air mass along the boundary, and usually produces precipitation. Cold fronts often follow a warm front or squall line.

i believe the answer is a or 1

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.