On
the
surface
of
the
continents
,
there
is
water
in
____________________
,
____________________
and
____________________
.
This
is
called
____________________
water
because
it
contains
____________________
____________________
salt
.
____________________
,
____________________
and
____________________
drink
fresh
water
.
This
is
called
drinking
water
.
Drinking
water
must
be
clean
.
