We
breathe
in
____________________
through
the
____________________
.
The
____________________
is
the
passage
connecting
the
throat
and
the
lungs
,
also
known
as
the
windpipe
.
The
oxygen
passes
through
the
trachea
.
The
____________________
are
tubes
at
the
bottom
of
the
trachea
that
connect
into
each
____________________
.
The
oxygen
passes
through
the
bronchi
into
the
lungs
.
The
oxygen
is
then
passed
into
the
____________________
through
the
____________________
.
The
blood
travels
around
the
body
____________________
to
deliver
____________________
and
pick
up
____________________
____________________
.
The
carbon
dioxide
goes
through
the
alveoli
into
the
lungs
.
It
passes
through
the
rest
of
the
organs
until
it
is
____________________
through
our
nose
or
our
mouth
.
The
____________________
is
a
muscle
that
helps
the
lungs
by
moving
down
to
inhale
air
and
moving
up
to
exhale
air
.
