拯救地球(Saving the Earth)

详细内容

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thepopulationoftheearthisincreasingveryfast.humansmustmaketheearthsupporttheincreasingpopulation.thishasmadeitnecessaryforagricultureandindustrytodeveloprapidly.

sucharapiddevelopmentproducesmoreandmorewaste,whichgoesintothewater,thesoilandtheair.someofitismadeharmless.however,wherethereistoomuchofit,thepoisonouswastemaydogreatharmtothethingsaroundthepeople.

whenfarmersaddfertilizertothesoiltomakeplantsgrowbetter,orusepoisontokillpests,poisonissentintotheair,thewaterandthesoil.whenbirds,fishandpeopleeatthegrain,drinkthewaterorbreaththeair,harmwillbedootheirhealth.

theairinbigcitiesisoftenmadeverydirtybycarsandfactories.millionsoftonsofwasteandpoisonousgasesaresentintotheairwiththesmoke.insomeplaces,littleisdoomakethesmokecleanbeforeitgoesintotheair.

fortunately,peoplearebeginningtorealizejusthowseriousthewholesituationis.inmanycountries,lawshavebeenmadetostopfactoriesfromsendingoutpoisonousgases.