Oxygen is the most common element in the earth's crust and makes up about 20% of the air we breathe.
(Oxygen; is; the most common element in the earth's crust) (Oxygen; makes up; about 20% of the air) (the air; breathe; we)
Oxygen Oxygen the air
is makes up breathe
the most common element in the earth's crust
about 20% of the air
we