英语阅读练习Doyouknowwhydifferentanimalsorpests(昆虫)havetheirspecialcolors?Colorsinthemseemtobeusedmainlytoprotectthemselves.Somebirdslikeeatinglocusts(蝗虫),butbirdscannoteasilycatchthem.Why?Itisbecauseloc

　　英语阅读练习

　　Doyouknowwhydifferentanimalsorpests(昆虫)havetheirspecialcolors?Colorsinthemseemtobeusedmainlytoprotectthemselves.

　　Somebirdslikeeatinglocusts(蝗虫),butbirdscannoteasilycatchthem.Why?Itisbecauselocustschangetheircolorstogetherwiththechangeofthecolorsofcrops(庄稼).Whencropsaregreen,locustslookgreen.Butastheharvesttimecomes,locustschangetothesamebrowncolorascropshave.Someotherpestswithdifferentcolorsfromplantsareeasilyfoundandeatenbyothers.Sotheyhavetohidethemselvesforlivesandappearonlyatnight.

　　Ifyoustudytheanimallife,you'llfindthemainuseofcoloringistoprotectthemselves.Bears,lionsandotheranimalsmovequietlythroughforests.Theycannotbeeasilyseenbyhunters(猎人).Thisisbecausetheyhavethecolorsmuchlikethetrees.

　　Haveyouevernoticedanevenstrangeract?Akindoffishintheseacansendoutakindofveryblackliquid(液体)whenitfacesdanger.Whiletheliquidspreadsover(散开),itsenemies(敌人)cannotfindit.Anditimmediatelyswimsaway.

　　1：Whydolocustschangetheircolors?____________

　　2:Howmanyanimalswhocan'tchangeprotectthemselves?_____________

　　3:Accordingtothepassage,whatcolourmaylocustsbeinsummer?_____________

　　4:Whatotherwayscananimalsprotectthemselves?(youmayuseChinesehere)________