Vertebrates
are
animals
that
have
a
backbone
or
____________________
____________________
,
also
called
vertebrae
.
They
are
classified
into
4
categories
:
Mammals
:
are
warm
-
blooded
animals
that
nurse
their
young
with
milk
and
have
fur
.
For
example
,
the
lion
.
Reptiles
:
are
cold
-
blooded
animals
which
lay
____________________
.
Their
skin
is
covered
with
hard
and
dry
____________________
.
For
example
,
the
crocodile
.
Birds
:
are
animals
that
have
____________________
,
____________________
,
and
lay
eggs
.
Many
,
but
not
all
,
birds
can
____________________
.
For
example
,
the
eagle
.
Amphibians
:
are
cold
-
blooded
animals
.
They
start
out
their
lives
living
in
the
____________________
with
gills
.
Later
they
develop
lungs
and
can
move
to
____________________
____________________
.
For
example
,
the
____________________
.
