Ecology(生态学)isthescienceofhowlivingcreaturesandplantsexisttogetheranddependoneachotherandonthelocalenvironment.Whereanen?vironmentisundisturbedtheecologyoftheareais1 innaturebalancebutifacreaturediesoutoranewspeciesis2 thentheecologyofthear?eawillbeupset.Inother3 thebalanceofnaturewillbe4 .
Manisapartofthe5 andhasdonemoretoupsettheecologyduring6 shortspanonearththan7 otherlivingcreature.Hehasdonethisbyhisignorancehis8 histhoughtlessfoolishnessandhisuncontrolledwastefulness.
Hehaspoisonedthe9 andpollutedbothlandandwater.Hehaswastedtheearth'snatural10 withnothoughtforthefutureandhasthoughtoutthemostdevastating(毁灭)waysofkillinghisfellowmenandeveryothersortoflifeatthesametime.
Sincemanhasdonesomuchdamageitisuptomantotryto11 thewayheactsifitisnotalreadytoo12 Ifthereistobeanyremedy(补救法)forourillsthatremedyultimatelyliesinthehandsofthe13 andthesoonertheystartdoingsomethingaboutitthe14 .
Oneofthemain15 oftheearth'stroublesisthattheworldistoo16 andthatthisoverpopulationisgrowingatanevei^increasingrate.Atthesametimeweare17 upournaturalresources―fuelsandmineralores―ataneverincreasingratewithno18 ofreplacingthem.
Formanyyearstheearthhasbeenunableto19 enoughfoodfortheserapidlyexpandingpopulationsandthepositionhasbeensteadilygettingworse20 someofourrichestsoil waslostandvastareasthatwereoncefertilelandswereturnedintodeserts.
1.A.kept B.stopped C.finished D.lost
2.A.foundout B.broughtin
C.brokendown D.tookout
3.A.cases B.speeches C.ways D.words
4.A.changed B.troubled C.kept D.damaged
5.A.environment B.situation C.science D.condition
6.A.their B.one's C.one D.his
7.A.any B.an C.all D.most
8.A.greed B.hope C.fear D.desire
9.A.sky B.heaven C.air D.space
10.A.energy B.resources