Do you know why different animals or pests(害虫) have their special colors? Colors in them seem to be mainly used to 1 themselves. Some birds like eating locusts(蝗虫), but birds cannot 2 catch them. Why? It is because locusts change their 3 with the change of the colors of crops. When crops are green, locusts look 4 . But as the harvest time comes, locusts change into the same brown color 5 crops have. Some other pests whose colors are 6 plants are easily found and eaten by 7 . So they have to hide themselves for lives and appear only 8 . If you 9 animals’ life, you’ll find the main use of colors is to protect 10 . Bears, lions and other animals 11 quietly through forests. They cannot be easily seen by hunters 12 their colors are much like the trees. Colors are useful not only on the land, but also in the 13 . A kind of fish can 14  a kind of black liquid( 液体) when they face danger. The liquid spreads over quickly, so they cannot be found by their enemies and can quickly swim away. That is 15 they can live safely though they are not strong at all. So colors are really useful to animals. 小题1: A．show B．protect C．kill D．interest 小题2: A．easily B．freely C．safely D．differently 小题3: A．sizes B．smells C．colors D．shapes 小题4: A．yellow B．red C．black D．green 小题5: A．so B．as C．like D．with 小题6: A．different from B．same as C．similar to D．opposite with 小题7: A．other B．others C．the others D．another 小题8: A．in the morning B．at noon C．at night D．in the daytime 小题9: A．study B．write C．draw D．work 小题10: A．them B．themselves C．it D．itself 小题11: A．run B．fight C．move D．eat 小题12: A．because B．so C．and D．although 小题13: A．forests B．desert C．sea D．mountains 小题14: A．keep out B．come out C．look out D．give out 小题15: A．why B．when C．how D．where