【Alllivingthingsontheearthneedotherlivingthingstolive.Nothinglivesalone.Mostanimalsmustliveinagroupandevenaplantgrowsclosetogetherwithothersofthesamekind.Sometimesonelivingthingkillsanotheroneeatsandth】

　　Alllivingthingsontheearthneedotherlivingthingstolive.Nothinglivesalone.Mostanimalsmustliveinagroupandevenaplantgrowsclosetogetherwithothersofthesamekind.Sometimesonelivingthingkillsanotheroneeatsandtheotheriseaten.Eachkindoflifeeatsanotherkindoflifeinordertoliveandtogethertheycreateafoodchain(链条).Somefoodchainsaresimplewhileothersarenot.Butallfoodchainsbeginwiththesunandallfoodchainsbecomebrokenupifoneofthelinks(链接)disappears.

　　Alllifeneedssunlighttoliveon.Butonlyplantscanusesunlightdirectly.Plantsare‘factories’.Theymakefoodfromsunlightwaterandthingsinthesoil(土壤)andair.Plantsfeedallotherlivingthings.Animalscanonlyusethesun’senergyafterithasbeenchangedintofoodbyplants.Someanimalsfeeddirectlyonplantsotherseatsmalleranimals.Meat-eatinganimalsareonlyeatingplantsindirectly.

　　Whatabouthumans?Wearemembersofmanyfoodchains.Weeatricevegetablesandfruitsandsoon.Wealsoeatmeatanddrinkmilk.Butweoftenbreakupthefoodchains.Wekillwildanimalsandalsomakeriverslakesandseaspolluted.Whentheseriverslakesandseasarepollutedthefishinthemcannotbeeaten.Ifweeatthefishwewillgetstrangeillnesses.

　　Eachformoflifeislinked(关联的)toallothers.Breakingthelinksputsalllifeindanger.

　　1.Whichlivingthingscanusethesun’senergydirectly?

　　A．Animals.

　　B．Plants.

　　C．Animalsandplants.

　　D．Alllivingthings.

　　2.Whooftendestroythefoodchains?

　　A．Humans.

　　B．Animals.

　　C．Plantsandanimals.

　　D．Humansandwildanimals.

　　3.Whichofthefollowingwouldbethebesttitleforthispassage?

　　A．TheSun’sEnergy

　　B．Plants

　　C．FoodChains

　　D．LivingThings