【Choosethewordsorexpressionsandcompletethepassage(选择最恰当的单词或词语，完成短文)1．Wehavealwaysbeenwarnedofthedangersoftheforestfires.Theycause1toaforest.Theykillmanyplantsandanimalsin】

　　Choosethewordsorexpressionsandcompletethepassage(选择最恰当的单词或词语，完成短文)

　　1．Wehavealwaysbeenwarnedofthedangersoftheforestfires.Theycause 1 toaforest.Theykillmanyplantsandanimalsinaneco-system,whichisagroupoflivingthingsandtheirenvironment.Buthaveyoueverheardofaforestfirethatcanbe 2 foraforest?

　　2．Peoplestartsomeofthefireswithspecialreasonstoactuallydowelltotheeco-system.

　　3．Infact,firesareanaturalpartofanyeco-system.Withoutfires,theoldestandlargesttreeswouldstopsunlightfromreachingtheforestfloor.Firescan 3 someoftheseoldtrees.Whenthetreesdie,theyprovidesomethinggoodfortheearth.Newtreescangrowstrongandhealthyintheirplace.

　　4．Sometreesevenneedfirestogrow.Thesetreesholdtheirseeds(种子)inside.Heatsfromafireallowthecoatoftheseedstoopenup.Thentheseedsfalltothegroundandhavethe4togrow.

　　5．Scientists,whoknowaboutnature’sneeds,startsomeofthesefires,calledcontrolledburns.Afireisstartedandkeptundercontrol.Thisway,thefiredoesnotspreadoutoftheareaor5 alargespaceoftheforest.Firescanbedangerousforanimals.Evenwhenanimalscontinuetoliveafterforestfires,theycangohungry 6 theirfoodhasbeendamagedinthefire.Small,controlledfiresmeanthatanimalswillnothavetomovefartofindfood.Aftersometime,smallplantsbegintogrow.Animalsreturnsoonaftertheplantsreturn.This 7 makesaneco-system.

　　6．Sothenexttimeyouhearaboutaforestfire,thinkaboutthegoodaswellasthebad.Itmaytakeaneweco-systemawhiletoreturn,butitwilllikelycomebackstrongerandhealthierthanever.

　　小题1:A．illnessB．difficultyC．damageD．flood小题2:A．helpfulB．powerfulC．harmfulD．awful