sentences: things usually travel from a source of that thing to other areas
docs: directions_to_get_somewhere is how_to_thing. migrating is natural_thing. geographical_thing is enduring_thing_localized. stuff is things. electricity is useful_way_to_transport_energy. place is somewhere_go. grayish_thing is localized_spatial_thing. leave_when is going_someplace. moving_things is not_at_rest. box is useful_when_moving_one's_household.