【单选题】A social system is （） of social relations that draws the behavior of its members toward the core values of the group.
A. a complex network
B. how a complex network
C. a complex network and
D. a network that is complex
A. a complex network
B. how a complex network
C. a complex network and
D. a network that is complex
【单选题】wEighing Among two to FivE kilogrAms in ADults, thE skin is thE lArgEst orgAn oF thE humAn BoDy.
【单选题】 Electoral politics in the United States has been dominated by two political parties since the administer of George Washington.
【单选题】 Although have there been better singers and actresses than Ethel Waters, none typifies the rise from rags to riches more dramatically than she
【单选题】 Statistics indicate that approximate every 22 years--within a range of 3 to 4 years--a major drought occursin the United States.
【单选题】sAn FrAnCisCo: itsContEmporAry issuEs
FAmous For its BEAutiFul sEtting, sAn FrAnCisCo is Built on A sEriEs oF stEEp hills loCAtED on thE northErn tip oF A pEninsulA At thE EntrAnCE to sAn FrAnCisCoBAy. thE BAy AnD its ExtEnsions, whiCh inCluDE sAn pABloBAy AnD suisunBAy, ConstitutE onE oF thE grEAt nAturAl hArBors oF thE worlD, EmBrACing nEArly 1,200 sq km (morE thAn 450 sq mi) oF wAtEr.BECAusE oF this, sAn FrAnCisCo wAs onCE thE mAjor pACiFiCCoAst sEAport oF thE unitED stAtEs. toDAy thE City is An importAnt CEntEr For FinAnCE, tEChnology, tourism, AnD CulturE. thE City wAs nAmED AFtEr sAn FrAnCisCoBAy, whiCh in turn wAs nAmED For sAint FrAnCis oFAssisi By EArly spAnish ExplorErs.
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thE pEoplE oF sAn FrAnCisCo CAn tAkE priDE in thEir City’s ACComplishmEnts.
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sAn FrAnCisCAns, AnD in somE CAsEs thEir CountErpArts in thEBAyArEA, hAvE suCCEssFully unDErtAkEn mAmmoth ConstruCtion projECts suCh As thE sAn FrAnCisCo-oAklAnDBAyBriDgE, thE golDEn gAtEBriDgE, AnD thEBAyArEA rApiD trAnsit systEm.
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sinCE At lEAst thE 1950s, sAn FrAnCisCAns hAvE Also EArnED A rEputAtion For tolErAnCE oF AnD rEspECt For DivErsity.
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During thE lAtE 1990s thE grEAtEst proBlEm in sAn FrAnCisCo’s inFrAstruCturE wAs thE muniCipAl rAilwAy. proportionAtEly morE sAn FrAnCisCAns rEly on puBliC trAnsportAtion thAn Do thE pEoplE in Any othErCAliForniA City, But riDErs ComplAinED oF sErious DElAys AnD ovErCrowDing. somE improvEmEnts wErE unDErwAy By 1999, AnD in thAt yEAr City votErs Also ApprovED mAjor ChAngEs in thE orgAnizAtionAl struCturE oF thE City’s trAnsportAtion DEpArtmEnts.
thE most sErious soCiAl proBlEms FACing thE City ArE not uniquE to sAn FrAnCisCo, But somE hAvE tAkEn on grEAtEr DimEnsions in thE City thAn thEy hAvE ElsEwhErE. onE suCh proBlEm is homElEssnEss.During thE ADministrAtion oF mAyorArtAgnos From 1988 to 1992, thE plAzA in Front oF City hAll BECAmE An EnCAmpmEnt For homElEss pEoplE, rEnDEring othEr usE impossiBlE AnD rAising puBliC hEAlth ConCErns.Agnos’s politiCAl opponEnts DuBBED it "CAmpAgnos" AnD thE situAtion ContriButED toAgnos’s DEFEAt in 1991. thE proBlEm oF homElEssnEss pErsists DEspitE thE EFForts oF City AgEnCiEs AnD privAtE ChAritiEs to proviDE shEltEr, hEAlth CArE, AnD Drug, AlCohol, AnD mEntAl hEAlth trEAtmEnt. in thE miD AnD lAtE 1990s mAyors FrAnk jorDAn AnD williEBrown Both sought to DisCourAgE homElEss pEoplE From living in puBliC spACE in thE Downtown ArEA AnD, inBrown’s CAsE, in golDEn gAtE pArk. howEvEr, rEsiDEnts oF othEr ArEAs ComplAinED thAt BECAusE oF thEsE projECts, thE DisplACED homElEss hAD movED into thEir nEighBorhooDs.
in othEr ArEAs thE City hAs mADE somE progrEss towArD ADDrEssing soCiAl proBlEms.As wAs truE ACross muCh oF thE nAtion, thE CrimE rAtE in sAn FrAnCisCo DroppED in thE 1990s, As DiD thE rAtE oF Drug-rElAtED violEnCE. in ADDition, somE puBliC homing projECts in sAn FrAnCisCo thAt wErE EspECiAlly pronE to violEnCE AnD Drug-rElAtED ACtivity wErE rAzED AnD rEBuilt with DEsigns ConsiDErED lEss likEly to EnCourAgE thosE ACtivitiEs. othEr puBliC homing projECts rECEivED stEppED up sECurity pAtrols.
somE soCiAl CritiCs hAvE pointED to An inCrEAsing EConomiC AnD soCiAl polArizAtion oF sAn FrAnCisCo’s populAtion. thosE who work in FinAnCE or high-tECh FiElDs ArE inCrEAsingly AFFluEnt, pushing rEnts AnD homE priCEs to Among thE highEst lEvEls in thE nAtion.At thE sAmE timE, pEoplE who lABor in thE sErviCE sECtor oFtEn work For thE minimum wAgE, CAnnot shArE thE AFFluEnt liFEstylEs ArounD thEm, AnD ArE hArD-prEssED to AFForD rising rEnts. thE DisAppEArAnCE oF mAny unionizED joBs in mAnuFACturing AnD
FAmous For its BEAutiFul sEtting, sAn FrAnCisCo is Built on A sEriEs oF stEEp hills loCAtED on thE northErn tip oF A pEninsulA At thE EntrAnCE to sAn FrAnCisCoBAy. thE BAy AnD its ExtEnsions, whiCh inCluDE sAn pABloBAy AnD suisunBAy, ConstitutE onE oF thE grEAt nAturAl hArBors oF thE worlD, EmBrACing nEArly 1,200 sq km (morE thAn 450 sq mi) oF wAtEr.BECAusE oF this, sAn FrAnCisCo wAs onCE thE mAjor pACiFiCCoAst sEAport oF thE unitED stAtEs. toDAy thE City is An importAnt CEntEr For FinAnCE, tEChnology, tourism, AnD CulturE. thE City wAs nAmED AFtEr sAn FrAnCisCoBAy, whiCh in turn wAs nAmED For sAint FrAnCis oFAssisi By EArly spAnish ExplorErs.
During thE lAtE 1990s thE grEAtEst proBlEm in sAn FrAnCisCo’s inFrAstruCturE wAs thE muniCipAl rAilwAy. proportionAtEly morE sAn FrAnCisCAns rEly on puBliC trAnsportAtion thAn Do thE pEoplE in Any othErCAliForniA City, But riDErs ComplAinED oF sErious DElAys AnD ovErCrowDing. somE improvEmEnts wErE unDErwAy By 1999, AnD in thAt yEAr City votErs Also ApprovED mAjor ChAngEs in thE orgAnizAtionAl struCturE oF thE City’s trAnsportAtion DEpArtmEnts.
thE most sErious soCiAl proBlEms FACing thE City ArE not uniquE to sAn FrAnCisCo, But somE hAvE tAkEn on grEAtEr DimEnsions in thE City thAn thEy hAvE ElsEwhErE. onE suCh proBlEm is homElEssnEss.During thE ADministrAtion oF mAyorArtAgnos From 1988 to 1992, thE plAzA in Front oF City hAll BECAmE An EnCAmpmEnt For homElEss pEoplE, rEnDEring othEr usE impossiBlE AnD rAising puBliC hEAlth ConCErns.Agnos’s politiCAl opponEnts DuBBED it "CAmpAgnos" AnD thE situAtion ContriButED toAgnos’s DEFEAt in 1991. thE proBlEm oF homElEssnEss pErsists DEspitE thE EFForts oF City AgEnCiEs AnD privAtE ChAritiEs to proviDE shEltEr, hEAlth CArE, AnD Drug, AlCohol, AnD mEntAl hEAlth trEAtmEnt. in thE miD AnD lAtE 1990s mAyors FrAnk jorDAn AnD williEBrown Both sought to DisCourAgE homElEss pEoplE From living in puBliC spACE in thE Downtown ArEA AnD, inBrown’s CAsE, in golDEn gAtE pArk. howEvEr, rEsiDEnts oF othEr ArEAs ComplAinED thAt BECAusE oF thEsE projECts, thE DisplACED homElEss hAD movED into thEir nEighBorhooDs.
in othEr ArEAs thE City hAs mADE somE progrEss towArD ADDrEssing soCiAl proBlEms.As wAs truE ACross muCh oF thE nAtion, thE CrimE rAtE in sAn FrAnCisCo DroppED in thE 1990s, As DiD thE rAtE oF Drug-rElAtED violEnCE. in ADDition, somE puBliC homing projECts in sAn FrAnCisCo thAt wErE EspECiAlly pronE to violEnCE AnD Drug-rElAtED ACtivity wErE rAzED AnD rEBuilt with DEsigns ConsiDErED lEss likEly to EnCourAgE thosE ACtivitiEs. othEr puBliC homing projECts rECEivED stEppED up sECurity pAtrols.
somE soCiAl CritiCs hAvE pointED to An inCrEAsing EConomiC AnD soCiAl polArizAtion oF sAn FrAnCisCo’s populAtion. thosE who work in FinAnCE or high-tECh FiElDs ArE inCrEAsingly AFFluEnt, pushing rEnts AnD homE priCEs to Among thE highEst lEvEls in thE nAtion.At thE sAmE timE, pEoplE who lABor in thE sErviCE sECtor oFtEn work For thE minimum wAgE, CAnnot shArE thE AFFluEnt liFEstylEs ArounD thEm, AnD ArE hArD-prEssED to AFForD rising rEnts. thE DisAppEArAnCE oF mAny unionizED joBs in mAnuFACturing AnD
【单选题】 According to the author, all of-the following evidence relating to the first birds was found EXCEPT
A．( nesting materials
B．( four skeletons in good condition
C．( two fragmented skeletons
D．( a single feather
A．( nesting materials
B．( four skeletons in good condition
C．( two fragmented skeletons
D．( a single feather
【单选题】 The author mentions "wispy marks" in line 19 as an example of
A．( an aspect of the lunar surface discovered through lunar missions
B．( a characteristic of large craters
C．( a discovery made through the use of Earth-based telescopes
D．( features that astronomers observed to be common to Earth and the Moon
A．( an aspect of the lunar surface discovered through lunar missions
B．( a characteristic of large craters
C．( a discovery made through the use of Earth-based telescopes
D．( features that astronomers observed to be common to Earth and the Moon
【单选题】 The Expressionistic artist was concerned not with the reality of the subject matter but with— inner nature and the emotions that it aroused
A．( it has
B．( its
C．( what its
D．( is it whether
A．( it has
B．( its
C．( what its
D．( is it whether
【分析解答题】rEADing 4 "Four stAgEs oF plAnEtAryDEvElopmEnt"
plAnEtAryDEvElopmEnt
→ in our stuDy oF thE plAnEtEArth, wE will FinD A Four-stAgE history oF plAnEtAry DEvElopmEnt. thE moon AnD All thE tErrEstriAl plAnEts hAvE pAssED through thEsE stAgEs, Although DiFFErEnCEs in thE wAy thE plAnEts wErE AltErED By thEsE stAgEs hAvE proDuCED DrAmAtiCAlly DiFFErEnt worlDs. thE moon, For ExAmplE, is muCh likEEArth, But its Evolution hAs BEEn DrAmAtiCAlly AltErED By its smAllEr sizE.As wE ExplorE thE solAr systEm, wE will DisCovEr not EntirEly nEw proCEssEs But rAthEr FAmiliAr EFFECts working in slightly DiFFErEnt wAys.
thE Four stAgEs
thE First stAgE oF plAnEtAry Evolution is DiFFErEntiAtion, thE sEpArAtion oF mAtEriAl ACCorDing to DEnsity.EArth now hAs A DEnsE CorE AnD A lowEr-DEnsity Crust, AnD thAt struCturE must hAvE originAtED vEry EArly.
DiFFErEntiAtion woulD hAvE oCCurrED EAsily iFEArth wErE moltEn whEn it wAs young. two sourCEs oF hEAt CoulD hAvE hEAtEDEArth. First, hEAt oF FormAtion woulD BE CrEAtED By in-FAlling mAtEriAl.A、mEtEoritE hittingEArth At high vEloCity ConvErts most oF its EnErgy oF motion into hEAt, AnD thE in-FAlling oF A lArgE numBEr oF mEtEoritEs CoulD rElEAsE trEmEnDous hEAt. iFEArth FormED rApiDly, this hEAt woulD hAvE ACCumulAtED muCh morE rApiDly thAn it CoulD lEAk AwAy, AnDEArth mAy hAvE BEEn moltEn whEn it FormED、A、sEConD sourCE oF hEAt rEquirEs morE timE to DEvElop. thE DECAy oF rADioACtivE ElEmEnts trAppED in thEEArth rElEAsEs hEAt grADuAlly; But, As soon AsEArth FormED, thAt hEAt woulD hAvE BEgun to ACCumulAtE AnD CoulD hAvE hElpED mEltEArth to FACilitAtE DiFFErEntiAtion. most oFEArth’s rADioACtivE ElEmEnts ArE now ConCEntrAtED in thE Crust, whErE thEy ContinuE to wArm AnD soFtEn thE roCk lAyErs.
EArth FormED By mAtEriAl FAlling togEthEr, But mEtEoritEs CoulD hAvE lEFt no trACE until A Crust soliDiFiED、onCEEArth hAD A hArD surFACE, thE mEtEoritEs CoulD Form CrAtErs. this sEConD stAgE in plAnEtAry Evolution, CrAtEring, wAs violEnt. thE hEAvy BomBArDmEnt wAs intEnsE BECAusE thE solAr nEBulA wAs FillED with roCky AnD iCy DEBris, AnD thE youngEArth wAs BAttErED By mEtEoritEs thAt pulvErizED thE nEwly Forming Crust. thE lArgEst mEtEoritEs BlAstED out CrAtEr BAsins hunDrEDs oF kilomEtErs in DiAmEtEr.As thE solAr nEBulA ClEArED, thE Amount oF DEBris DECrEAsED, AnD thE lEvEl oF CrAtEring FEll to its prEsEnt low lEvEl.Although mEtEoritEs still oCCAsionAlly strikEEArth AnD Dig CrAtErs, CrAtEring is no longEr thE DominAnt inFluEnCE onEArth’s gEology.As wE CompArE othEr worlDs withEArth, wE will DisCovEr trACEs oF this intEnsE pErioD oF CrAtEring, thE hEAvy BomBArDmEnt, on EvEry olD surFACE in thE solAr systEm.
→ thE thirD stAgE, FlooDing, no DouBt BEgAn whilE CrAtEring wAs still intEnsE. thE FrACturing oF thE Crust AnD thE hEAting CAusED By rADioACtivE DECAy AllowED moltEn roCk just BElow thE Crust to wEll up through FissurEs AnD FlooD thE DEEpEr BAsins. wE will DisCuss suCh FlooDED BAsins on othEr worlDs, suCh As thE moon, But All trACEs oF this EArly lAvA FlooDing hAvE BEEn DEstroyED By lAtEr gEologiCAl ACtivity inEArth’s Crust. onEArth, FlooDing ContinuED As thE AtmosphErE CoolED AnD wAtEr FEll As rAin, Filling thE DEEpEst BAsins to proDuCE thE First oCEAns.
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notiCE thAt onEArth FlooDing involvEs Both lAvA AnD wAtEr, A CirCumstAnCE thAt wE will not FinD on most worlDs.
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thE Fourth stAgE, slow surFACE Evolution, hAs ContinuED For thE lAst 3.5 Billion yEArs or morE.
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EArth’s surFACE is ConstAntly ChAnging As sECtions oF Crust sliDE ovEr EACh othEr, push up mountAins, AnD shiFt ContinEnts.
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Almost All trACEs oF thE Firs
plAnEtAryDEvElopmEnt
→ in our stuDy oF thE plAnEtEArth, wE will FinD A Four-stAgE history oF plAnEtAry DEvElopmEnt. thE moon AnD All thE tErrEstriAl plAnEts hAvE pAssED through thEsE stAgEs, Although DiFFErEnCEs in thE wAy thE plAnEts wErE AltErED By thEsE stAgEs hAvE proDuCED DrAmAtiCAlly DiFFErEnt worlDs. thE moon, For ExAmplE, is muCh likEEArth, But its Evolution hAs BEEn DrAmAtiCAlly AltErED By its smAllEr sizE.As wE ExplorE thE solAr systEm, wE will DisCovEr not EntirEly nEw proCEssEs But rAthEr FAmiliAr EFFECts working in slightly DiFFErEnt wAys.
thE Four stAgEs
thE First stAgE oF plAnEtAry Evolution is DiFFErEntiAtion, thE sEpArAtion oF mAtEriAl ACCorDing to DEnsity.EArth now hAs A DEnsE CorE AnD A lowEr-DEnsity Crust, AnD thAt struCturE must hAvE originAtED vEry EArly.
DiFFErEntiAtion woulD hAvE oCCurrED EAsily iFEArth wErE moltEn whEn it wAs young. two sourCEs oF hEAt CoulD hAvE hEAtEDEArth. First, hEAt oF FormAtion woulD BE CrEAtED By in-FAlling mAtEriAl.A、mEtEoritE hittingEArth At high vEloCity ConvErts most oF its EnErgy oF motion into hEAt, AnD thE in-FAlling oF A lArgE numBEr oF mEtEoritEs CoulD rElEAsE trEmEnDous hEAt. iFEArth FormED rApiDly, this hEAt woulD hAvE ACCumulAtED muCh morE rApiDly thAn it CoulD lEAk AwAy, AnDEArth mAy hAvE BEEn moltEn whEn it FormED、A、sEConD sourCE oF hEAt rEquirEs morE timE to DEvElop. thE DECAy oF rADioACtivE ElEmEnts trAppED in thEEArth rElEAsEs hEAt grADuAlly; But, As soon AsEArth FormED, thAt hEAt woulD hAvE BEgun to ACCumulAtE AnD CoulD hAvE hElpED mEltEArth to FACilitAtE DiFFErEntiAtion. most oFEArth’s rADioACtivE ElEmEnts ArE now ConCEntrAtED in thE Crust, whErE thEy ContinuE to wArm AnD soFtEn thE roCk lAyErs.
EArth FormED By mAtEriAl FAlling togEthEr, But mEtEoritEs CoulD hAvE lEFt no trACE until A Crust soliDiFiED、onCEEArth hAD A hArD surFACE, thE mEtEoritEs CoulD Form CrAtErs. this sEConD stAgE in plAnEtAry Evolution, CrAtEring, wAs violEnt. thE hEAvy BomBArDmEnt wAs intEnsE BECAusE thE solAr nEBulA wAs FillED with roCky AnD iCy DEBris, AnD thE youngEArth wAs BAttErED By mEtEoritEs thAt pulvErizED thE nEwly Forming Crust. thE lArgEst mEtEoritEs BlAstED out CrAtEr BAsins hunDrEDs oF kilomEtErs in DiAmEtEr.As thE solAr nEBulA ClEArED, thE Amount oF DEBris DECrEAsED, AnD thE lEvEl oF CrAtEring FEll to its prEsEnt low lEvEl.Although mEtEoritEs still oCCAsionAlly strikEEArth AnD Dig CrAtErs, CrAtEring is no longEr thE DominAnt inFluEnCE onEArth’s gEology.As wE CompArE othEr worlDs withEArth, wE will DisCovEr trACEs oF this intEnsE pErioD oF CrAtEring, thE hEAvy BomBArDmEnt, on EvEry olD surFACE in thE solAr systEm.
→ thE thirD stAgE, FlooDing, no DouBt BEgAn whilE CrAtEring wAs still intEnsE. thE FrACturing oF thE Crust AnD thE hEAting CAusED By rADioACtivE DECAy AllowED moltEn roCk just BElow thE Crust to wEll up through FissurEs AnD FlooD thE DEEpEr BAsins. wE will DisCuss suCh FlooDED BAsins on othEr worlDs, suCh As thE moon, But All trACEs oF this EArly lAvA FlooDing hAvE BEEn DEstroyED By lAtEr gEologiCAl ACtivity inEArth’s Crust. onEArth, FlooDing ContinuED As thE AtmosphErE CoolED AnD wAtEr FEll As rAin, Filling thE DEEpEst BAsins to proDuCE thE First oCEAns.
thE Fourth stAgE, slow surFACE Evolution, hAs ContinuED For thE lAst 3.5 Billion yEArs or morE.
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