____________________
and
____________________
to
are
used
to
express
____________________
obligation
whereas
____________________
to
and
____________________
express
a
____________________
obligation
.
____________________
is
used
to
express
a
____________________
-
____________________
obligation
,
an
obligation
that
comes
from
the
individual's
____________________
.
Have
to
expresses
an
obligation
coming
from
an
____________________
source
.
____________________
to
usually
implies
a
____________________
obligation
.
