One
of
the
four
____________________
of
____________________
for
the
planet
is
to
reduce
our
____________________
on
____________________
fuels
,
such
as
oil
,
____________________
and
gas
.
To
do
this
we
must
increase
the
use
of
____________________
sources
of
energy
.
These
include
____________________
power
(
taking
energy
from
the
sun
)
,
wind
power
and
____________________
power
.
We
call
these
sources
____________________
,
which
means
that
the
planet
can
____________________
these
resources
quickly
by
natural
processes
and
are
,
in
theory
at
least
,
____________________
.
