A
long
time
ago
,
one
kind
of
wise
____________________
called
human
being
appeared
in
the
natural
world
.
After
many
years
,
in
today's
world
,
that
creature
became
the
____________________
of
the
world
.
While
they
were
getting
more
and
more
intelligent
,
an
ambition
came
out
.
____________________
beings
wanted
to
conquer
the
whole
natural
____________________
.
However
they
haven't
succeeded
yet
.
The
role
of
the
natural
world
in
human
society
hasn't
changed
.
It
is
both
as
a
friend
and
an
____________________
to
human
society
.
