1. The larvae of house-flies are known as _______.   caterpillars   maggots   pupas   Hint Half-n-half Clue   2. Mammals have _______ glands which secrete milk.   adrenal   pituitary   mammary   Half-n-half Clue   3. The lateral lines of fish are sensitive to the vibrations of water.   False   True   4. Slow-worms and grass-snakes can be classified as reptiles which is one of the classes of vertebrates.   False   True   5. Each of the hind feet of a frog has 4 toes.   True   False   6. _______ animals live on trees.   Arboreal   Aerial   Terrestrial   Half-n-half Clue   7. Which of the following animals is cold-blooded?   Crocodile   Elephant   Leopard   Seal   Whale   Half-n-half Clue