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Thehumannoseisanunderratedtool.Humansareoftenthoughttobeinsensitivesmellerscomparedwithanimals,1thisislargelybecause,2animals,westandupright.Thismeansthatournosesare3toperceivingthosesmellswhichfloatthroughtheair,4themajorityofsmellswhichsticktosurfaces.Infact5,weareextremelysensitivetosmells,6wedonotgenerallyrealizeit.Ournosesarecapableof7humansmellsevenwhentheseare8tofarbelowonepartinonemillion.Strangely,somepeoplefindthattheycansmellonetypeofflowerbutnotanother,9othersaresensitivetothesmellsofbothflowers.Thismaybebecausesomepeopledonothavethegenesnecessarytogenerate10smellreceptorsinthenose.Thesereceptorsarethecellswhichsensesmellsandsend11tothebrain.However,ithasbeenfoundthatevenpeopleinsensitivetoacertainsmell12cansuddenlybecomesensitivetoitwhen13toitoftenenough.Theexplanationforinsensitivitytosmellseemstobethatbrainfindsit14tokeepallsmellreceptorsworkingallthetimebutcan15newreceptorsifnecessary.Thismay16explainwhywearenotusuallysensitivetoourownsmellswesimplydonotneedtobe.Wearenot17oftheusualsmellofourownhousebutwe18newsmellswhenwevisitsomeoneelse's.Thebrainfindsitbesttokeepsmellreceptors19forunfamiliarandemergencysignals20thesmellofsmoke,whichmightindicatethedangeroffire.1.[A]although[B]as[C]but[D]while2.[A]above[B]unlike[C]excluding[D]besides3.[A]limited[B]committed[C]dedicated[D]confined4.[A]catching[B]ignoring[C]missing[D]tracking5.[A]anyway[B]though[C]instead[D]therefore6.[A]evenif[B]ifonly[C]onlyif[D]asif7.[A]distinguishing[B]discovering[C]determining[D]detecting8.[A]diluted[B]dissolved[C]determining[D]diffused9.[A]when[B]since[C]for[D]whereas10.[A]unusual[B]particular[C]unique[D]typical11.[A]signs[B]stimuli[C]messages[D]impulses12.[A]atfirst[B]atall[C]atlarge[D]attimes13.[A]subjected[B]left[C]drawn[D]exposed14.[A]ineffective[B]incompetent[C]inefficient[D]insufficient15.[A]introduce[B]summon[C]trigger[D]create16.[A]still[B]also[C]otherwise[D]nevertheless17.[A]sure[B]sick[C]aware[D]tired18.[A]tolerate[B]repel[C]neglect[D]notice19.[A]available[B]reliable[C]identifiable[D]suitable20.[A]similarto[B]suchas[C]alongwith[D]asidefromThehomelessmakeupagrowingpercentageofAmerica'spopulation.1homelessnesshasreachedsuchproportionsthatlocalgovernmentcan'tpossibly2.Tohelphomelesspeople3independence,thefederalgovernmentmustsupportjobtrainingprograms,4theminimumwage,andfundmorelow-costhousing.5everyoneagreesonthenumbersofAmericanswhoarehomeless.Estimates6anywherefrom600,000to3million.7thefiguremayvary,analystsdoagreeonanothermatter:thatthenumberofthehomelessis8,oneofthefederalgovernment'sstudies9thatthenumberofthehomelesswillreachnearly19millionbytheendofthisdecade.Findingwaysto10thisgrowinghomelesspopulationhasbecomeincreasinglydifficult.11whenhomelessindividualsmanagetofinda12thatwillgivethemthreemealsadayandaplacetosleepatnight,agoodnumberstillspendthebulkofeachday13thestreet.Partoftheproblemisthatmanyhomelessadultsareaddictedtoalcoholordrugs.Andasignificantnumberofthehomelesshaveseriousmentaldisorders.Manyothers,14notaddictedormentallyill,simplylacktheeveryday15skillsneededtoturntheirlives16.BostonGlobereporterChrisReedynotesthatthesituationwillimproveonlywhenthereare17programsthataddressthemanyneedsofthehomeless.18EdwardZlotkowski,directorofcommunityserviceatBentleyCollegeinMassachusetts,19it.Therehastobe20ofprograms.Whatweneedisapackagedeal.1.[A]Indeed[B]Likewise[C]Therefore[D]Furthermore2.[A]stand[B]cope[C]approve[D]retain3.[A]in[B]for[C]with[D]toward4.[A]raise[B]add[C]take[D]keep5.[A]Generally[B]Almost[C]Hardly[D]Not6.[A]cover[B]change[C]range[D]differ7.[A]Nowthat[B]Although[C]Provided[D]Exceptthat8.[A]inflating[B]expanding[C]increasing[D]extending9.[A]predicts[B]displays[C]proves[D]discovers10.[A]assist[B]track[C]sustain[D]dismiss11.[A]Hence[B]But[C]Even[D]Only12.[A]lodging[B]shelter[C]dwelling[D]house13.[A]searching[B]strolling[C]crowding[D]wandering14.[A]when[B]once[C]while[D]whereas15.[A]life[B]existence[C]survival[D]maintenance16.[A]around[B]over[C]on[D]up17.[A]complex[B]comprehensive[C]complementary[D]compensating18.[A]So[B]Since[C]As[D]Thus19.[A]puts[B]interprets[C]assumes[D]makes20.[A]supervision[B]manipulation[C]regulation[D]coordinationBy1830theformerSpanishandPortuguesecolonieshadbecomeindependentnations.Theroughly20million1ofthesenationslooked2tothefuture.BorninthecrisisoftheoldregimeandIberianColonialism,manyoftheleadersofindependence3theidealsofrepresentativegovernment,careers4totalent,freedomofcommerceandtrade,the5toprivateproperty,andabeliefintheindividualasthebasisofsociety.6therewasabeliefthatthenewnationsshouldbesovereignandindependentstates,largeenoughtobeeconomicallyviableandintegratedbya7setoflaws.Ontheissueof8ofreligionandthepositionofthechurch,9,therewaslessagreement10theleadership.RomanCatholicismhadbeenthestatereligionandtheonlyone11bytheSpanishcrown.12mostleaderssoughttomaintainCatholicism13theofficialreligionofthenewstates,somesoughttoendthe14ofotherfaiths.ThedefenseoftheChurchbecamearallying15fortheconservativeforces.Theidealsoftheearlyleadersofindependencewereoftenegalitaria