Colour helps you see things．But man and some monkeys and apes(猿) are the only mammals(哺乳动物) that can see colour．1 any other mammals，such as the dog，the world 2 a black-white photo．Dogs hunt mainly by listening and smelling．
Like 3 animals，dogs see best when things move．The animals they hunt seem to know this．A rabbit or deer will freeze when they find that they are being hunted．Then the dog 4 see it at all
Birds can see colour．They need to，because when they fly，they need to find places to land．Colour helps them know 5 the place is and what it is like so that they are able to catch flying things in the air or to 6 something they think safe．
Some birds see things even 7 than man．The birds that eat bugs(虫子) can see them from far away．And even a very young bird can see a house 8 the sky．So good eyes and being able to see colours help birds 9 food and also help them find out 10 there are other animals that are dangerous to them．
