1
.
A
healthy
environment
is
dependent
____________________
how
well
people
manage
their
resources
.
2
.
We
should
do
everything
____________________
our
power
to
protect
these
species
.
3
.
There
are
complex
systems
____________________
the
earth's
surface
that
people
do
not
fully
understand
.
4
.
I
wonder
how
the
leopard
and
rhino
,
which
are
____________________
the
most
threatened
species
,
can
survive
.
5
.
The
effect
____________________
tourism
will
be
so
huge
____________________
the
world
that
we
cannot
imagine
them
.
