PLEASE HELP The skeleton of a shark is made of bone.
 a. true
 b. false
 17 Answer: 
 A cold-blooded animal is able to maintain a constant body
 temperature despite the temperature of its surroundings.
 a. true
 b. false
 18 Answer: 
 Many frogs have bumps behind their eyes that contain a poisonous
 liquid.
 a. true
 b. false
 19 Answer: 
 Jawless fish are the most primitive of all the fish.
 a. true
 b. false
 20 Answer: 
 During the winter, frogs and toads go into a deep sleep called
 molting.
 a. true
 b. false