Question

which air mass - warm or cold - is pushed above the other air mass as the front moves?
warm
cold
what weather forms as the front boundary advances and pushes an air mass up? rain clouds/rain/clouds
true
false
when a rapidly moving cold air mass runs into a slowly moving warm air mass
warm front
cold front

Explanation:

First Question (Which air mass – warm or cold – is pushed above the other as the front moves?):

In meteorology, cold air is denser than warm air. When a front moves, the denser cold air mass pushes the less - dense warm air mass upward. So the cold air mass stays below and the warm air mass is pushed above.

When an air mass is pushed up, it cools adiabatically. As the air cools, water vapor in it condenses to form clouds, and often precipitation (rain) occurs. So rain clouds (or rain, or clouds) form. The "True" option is correct as this is a basic meteorological principle.

When a rapidly moving cold air mass meets a slowly moving warm air mass, a cold front is formed. Cold fronts are characterized by the cold air mass pushing the warm air mass. The "Cold Front" option is correct.

Answer:

cold (the option with "cold" selected, as cold air is denser and pushes warm air above)

Second Question (What weather forms as the front boundary advances and pushes an air mass up? Rain clouds/rain/clouds):