Living things use what for oxidation of carbohydrates, proteins, and fats.
O oxygen
O carbon
O hydrogen
O nitrogen

Study the image of this rock.which characteristic best supports its formation from sedimentary processes? it has many layers.it is coarse-grained.its grain shape is round.its texture is non-banded.

How is the carbon cycle related to global warming ?

What are levels of ecology and how can we remember them