an organism requires energy for growth and repair & a human is a kind of organism ->  a human requires energy for growth and repair  nutrients are a source of energy for living things & food contains nutrients ->  food is a source of energy for living things  food is a source of energy for living things & a human is a kind of living thing ->  food is a source of energy for humans  a human requires energy for growth and repair & food is a source of energy for humans -> humans require energy from food for growth and repair