【单选题】 Usually pitched in the of C, （） may be tuned to B flat by means of a slide.
A. the bugle
B. because of the bugle
C. the bugle that
D. but the bugle
A. the bugle
B. because of the bugle
C. the bugle that
D. but the bugle
【单选题】rAin is slight ACiDiC EvEn in unpollutED Air, BECAusE CArBon DioxiDE in thE AtmosphErE AnD othEr nAturAl ACiD-Forming gAsEs DissolvE in thEwAtEr.
【单选题】in miCrophotogrAphy, proCEssEs photogrAphiC ArE usED to rEproDuCE tExt or illustrAtions on Film in sizEs rEquiring mAgniFiCAtion For rEADing or viEwing thEm.
【单选题】 Ice crystals in a glacier tends to melt and recrystallize within a brief moment of travel on a downhill glide.
【单选题】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.
![]()
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.
![]()
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.
【单选题】 (Rarely has) a technological development (had) as great an (impact on) society as the rapid (grow) of electronics.
A．Rarely has
B．had
C．impact on
D．grow
A．Rarely has
B．had
C．impact on
D．grow
【多选题】 _________ Jane and Mary like different things, they are great friends.
A．Since
B．Despite
C．For
D．Although
A．Since
B．Despite
C．For
D．Although
【单选题】 Made of hard wood, the boomerang is roughly V-shaped, with arms — skewed
A．( of slightly
B．( are slightly
C．( slightly
D．( that those are slightly
A．( of slightly
B．( are slightly
C．( slightly
D．( that those are slightly
【单选题】 According to the passage, which of the following is the LEAST amount of time necessary for glacial ice to form
A．(Several months
B．(Several years
C．(At least fifty years
D．(A century
A．(Several months
B．(Several years
C．(At least fifty years
D．(A century
【单选题】 The chief (commercial) source of bromine is ocean water, from (what) the element is extracted by (means of) chemical (replacement) by chlorine.
A．commercial
B．what
C．means of
D．replacement
A．commercial
B．what
C．means of
D．replacement
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