fiberglass are usually tongues of sound age in elevation
glass_wool is not fibreglass. fibreglass_batting is not glass_wool. fibreglass_batting is glass_wool. hourglass is ancient_form_of_measuring_time. hourglass is old_way_of_telling_time. fiberglass is not glass. fiberglass is glass. glass_wool is fibreglass. hourglass is sandglass.