What does cyclical mean

Biomass can be used to generate electricity. biomass relies heavily on agricultural crops. plants release carbon dioxide and water in combustion. plants use photosynthesis to originally generate the energy that is needed. the chemical energy of these plants all started with what energy source?

Which statement names a physical property of wood? wood does not rustwood can burnwood can rotwood is softer than coal

What was the impact of the concordat of worms?