関連ワード:  is biomass renewable energy resource    is biomass renewable energy source    biomass is renewable energy source true or false    is biomass renewable exhaustible natural energy resource    is biomass a non renewable energy resource    is biomass/biofuels a renewable energy resource    is biomass energy renewable or nonrenewable resource    biomass is a non renewable energy resource true or false    is biomass a clean energy source    is biomass a sustainable energy source