A
unit
of
matter
may
be
classed
as
a
____________________
if
,
when
observed
under
a
microscope
,
it
is
at
least
____________________
times
longer
that
it
is
thick
.
Short
fibres
are
also
known
as
____________________
fibres
.
These
are
from
15
to
____________________
long
.
Longer
fibres
,
even
up
to
600m
like
some
____________________
fibres
,
are
known
as
____________________
fibres
.
Textile
fibres
can
be
classified
according
to
their
source
-
that
is
,
according
to
where
they
come
from
.
The
two
main
categories
are
____________________
and
manufactured
.
Natural
fibres
come
from
____________________
and
plants
.
____________________
fibres
are
those
that
come
from
animals
.
____________________
fibres
are
those
that
come
from
plants
.
Manufactured
fibres
are
made
through
____________________
processes
and
cannot
be
found
in
nature
.
____________________
fibres
are
made
solely
from
chemical
polymers
.
____________________
fibres
are
made
from
a
mix
of
chemical
and
cellulose
monomers
.
