1. A whale is _______.   an amphibian   a mammal   a bird   a fish   a reptile   Hint Half-n-half Clue   2. A _______ is cold-blooded.   snake   polar bear   3. A _______ is a mammal.   crocodile   mackerel   frog   monkey   crow   Half-n-half Clue   4. A _______ is a fish.   dove   sardine   lizard   frog   horse   Half-n-half Clue   5. A _______ is a bird.   salamander   pigeon   crocodile   cow   mackerel   Half-n-half Clue   6. A _______ is a vertebrate.   snake   starfish   7. A mosquito is _______.   a vertebrate   an invertebrate