When
people
think
of
soil
,
they
only
think
of
muddy
____________________
stuff
under
their
feet
.
However
,
there
are
more
than
750
different
types
of
____________________
and
each
of
them
has
its
own
____________________
living
in
it
.
It
?
s
said
that
in
a
single
gram
of
soil
,
there
could
be
as
many
as
50
,
000
____________________
of
microscopic
organisms
,
or
____________________
.
Soil
affects
the
____________________
of
the
food
we
eat
,
the
air
we
breathe
and
the
water
we
use
and
____________________
.
It
provides
people
with
whatever
is
necessary
in
their
lives
.
Running
out
of
healthy
soil
means
that
people
won't
be
able
to
continue
____________________
or
planting
activities
which
would
create
more
____________________
for
people
.
