There
____________________
more
than
4
,
000
different
____________________
of
mammals
on
Earth
.
The
____________________
is
one
kind
of
bat
,
which
weighs
0
.
05
ounces
.
The
____________________
is
the
blue
____________________
,
which
can
be
100
feet
long
and
weigh
150
tons
.
It
____________________
important
to
know
that
____________________
are
mammals
,
probably
the
most
____________________
group
of
them
,
because
we
are
the
____________________
group
able
to
read
and
write
.