What has skeleton made of tough tissue that contains a protein called collagen?
mammals rocks animals sharks a fish cows humans plants
A B C D E F G H
Sharks have a cartilage skeleton.
Sharks have a skeleton made of tough tissue that contains a protein called collagen
What has skeleton made of tough tissue that contains a protein called collagen? (A) mammals (B) rocks (C) animals (D) sharks (E) a fish (F) cows (G) humans (H) plants