C

NotmanyyearsagosomeAmericanfarmersbegantocomplainabouthawks(鹰).Thehawkswerekillingchickens.Thefarmersdidnotknowwhattodo.Theywenttothegovernmentofficialsandaskedforhelp.

Theofficialssaid“We’llpayyouforeachhawkyoukill.”Thefarmersbegantokillthehawks.Manyhawkswerekilledbutthefarmersnowhadanotherproblem.Thefieldmiceweregrowinginnumberandtheywereeatingupthefarmers’corn.Hawkseatnotonlychickensbutalsofieldmice.Theyeatmorefieldmicethanchickens.Butifthefarmershadknownthattheywouldnothaveupset(打乱)thebalanceofnature.InonepartoftheUSAtherearedeerwhicheatakindofwildrose.Thedeerareeatenbymountainlions.Thenumberofdeermountainlionsandwildrosedoesnotchangemuchifpeoplestayawayfromthem.Iftherearetoomanydeermountainlionswillincreaserapidlyinnumberandkillmanydeer.Iftherearetoomanymountainlionstherewillbefewerdeerandtherewillbemoreroses.

Itisalwaysnecessaryforustokeepthebalanceofnature.Thegovernmentoncekilledalmostallthemountainlionstoprotectthedeer.Soonthereweresomanydeerthattheyateupallthewildroses.Thentheybegantoeatthegreenleavesofyoungtreeswhichwereimportanttothefarmers.

Sothefarmersprotectedtheirtreesfromthedeer.Thedeerhadnothingtoeatandmanyofthemdied.

Thegovernmentlearnedavaluablelessonfromnature.

44.Whathadhappenedafterthehawkswerekilled?

A.Peoplewouldn’tworryabouttheirchickens.

B.Thenumberofthefieldmicebecametoolarge.

C.Thenumberofthefieldmicebecamesmall.

D.Thefieldmicewereeatingupthefarmers’corn.

45.WhydidAmericanpeoplehavetoprotecttheirtrees?

A.Becausethemountainlionsdestroyedthetrees.

B.Becausethereweresomanydeerthattheybegantoeatthegreenleaves.

C.Becausetheywantedthetreestogrowwell.

D.Becausethetreesaremoreimportantthanthedeer.

46.Whatcanwelearnfromthearticle?

A.Wemustkeepthebalanceofnature.

B.Wemustnotkillanyanimals.

C.wemustfeedthehawkswithourcorntokeepthebalanceofnature.

D.BothAandB.