sentences: a home is a kind of building & energy is used for heating a building by a heating system ->  energy is used for heating a home  solar energy is a renewable / inexhaustible resource & solar energy is a kind of energy ->  solar energy is a kind of renewable resource and a kind of energy  energy is used for heating a home & solar energy is a kind of renewable resource and a kind of energy -> solar energy is a kind of renewable resource that is used for heating a home