Look around at the plants that produce oxygen, the animals that breathe oxygen and produce waste, and the decomposers, such as fungi, that turn those wastes into soil nutrients that feed the plants.
(soil nutrients; feed; the plants) (the plants; produce; oxygen) (the animals; breathe; oxygen) (the animals; produce; waste) (fungi; turn; those wastes; into soil nutrients)
soil nutrients the plants the animals the animals fungi
feed produce breathe produce turn
the plants
oxygen
oxygen
waste
those wastes into soil nutrients