Our
____________________
and
organs
absorb
____________________
in
order
to
carry
out
yhe
funcion
of
____________________
.
The
oxygen
that
we
breathe
in
passes
into
our
____________________
,
where
it´s
transported
to
our
muscules
.
Our
muscules
absorb
oxygen
and
expel
____________________
____________________
.
There
is
an
exchange
of
carbon
dioxide
between
the
____________________
,
and
the
____________________
.
Then
we
____________________
this
gas
as
we
____________________
out
.
