(top of page) Oxygen Oxygen is easily obtained when healthy plants do their job of changing carbon dioxide into oxygen.
(top of page) Oxygen Oxygen; is easily obtained; T:when healthy plants do their job of changing carbon dioxide into oxygen) (healthy plants; do; their job of changing carbon dioxide into oxygen)
top of page) Oxygen Oxygen healthy plants
is easily obtained do
T:when healthy plants do their job of changing carbon dioxide into oxygen
their job of changing carbon dioxide into oxygen