What did darwin use to describe the ability of an individual to survive ?

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.

Acell in the human nervous system whose primary function is to form myelin and the blood-brain barrier, respond to injury, remove debris, and enhance learning and memory is called a(n) cell.

Idon’t understand and i need the answer! you