Which best explains how a heat pump can heat a room? Cold air from the house is moved through pipes, where it absorbs thermal energy.
Warm air from outside is pushed into the house to replace the cold air.
Combustion warms the air when chemical energy is transferred to thermal energy.
Fuel is used to move a piston, which pushes warm air into the house.

equal distribution i think.

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation:

the correct answer is 2 and 4