Plastics
are
materials
formed
by
____________________
which
are
made
from
long
____________________
of
____________________
atoms
.
Depending
on
their
____________________
they
can
be
:
.
-
____________________
plastics
obtained
directly
from
____________________
____________________
materials
.
-
____________________
plastics
made
from
____________________
extracted
from
____________________
,
natural
____________________
and
____________________
.
____________________
is
the
transformation
of
____________________
materials
and
____________________
into
plastics
.
