The lungs work harder to absorb this oxygen out of the air.
(The lungs; work harder; to absorb this oxygen out of the air) Context(The lungs work harder,List([0, 21))):(The lungs; work harder to absorb; this oxygen; out of the air)
The lungs work harder,List([0, 21))
The lungs The lungs
work harder work harder to absorb
to absorb this oxygen out of the air
this oxygen out of the air