a forest canopy is a kind of opaque object
canopy is not external_anatomical_part. canopy is external_anatomical_part. window_covering is opaque_thing. canopy_closure_dense is forest. opaque_covering is not opaque_thing. canopy_closure_dense is not forest. opaque_covering is opaque_thing. smoke is opaque_thing. umbrella is canopy. forest_clearing is open_canopy_closure.