○○○ microscopic ⪢⪢
You will often see
snakes flicking their tongue in and out. Again this
snake is not being rude. It is actually tasting the air - collecting microscopic particles which it can analyze using a special organ in the roof of its mouth.
http://qindex.info/i.php?x=14809
○○○ vertebrate ⪢⪢
Snakes are also vertebrates which means that they have a backbone. Actually
snakes are almost ALL backbone! A
snake's skeleton is most made of its skull, the vertebrate (or bones of the spine) and ribs.
http://qindex.info/i.php?x=16217