Classify each animal according to whether or not it has an internal sketeleton .

Classify each animal according to whether or not it has an internal sketeleton .

Classify each animal according to whether or not it has an internal sketeleton .

Classify each animal according to whether or not it has an internal sketeleton .

Classify each animal according to whether or not it has an internal sketeleton .

Classify each animal according to whether or not it has an internal sketeleton .