【单选题】The discovery of freezing has changed our eating habits more than any other related invention. Because many foods contain large amounts of water, they freeze solidly at or just below 32 degrees Fahrenheit. When we lower the temperature to well below the freezing point and prevent air from penetrating the food, we retard the natural process of decay that causes food to spoil. Freezing preserves the flavor and nutrients of food better than any other preservation method. When properly prepared and packed, foods and vegetables can be stored in the freezer for one year.
Most vegetables and some fruits need blanching before they are frozen, and to avoid this step would be an expensive mistake. The result would be a product largely devoid of vitamins and minerals. Proper blanching curtails the enzyme action, which vegetables require during their growth and ripening but which continues after maturation and will lead to decay unless it is almost entirely stopped by blanching. This process is done in two ways, either by plunging vegetables in a large amount of rapidly boiling water for a few minutes or by steaming them. For steam blanching, it is important that timing begin when the water at the bottom of the pot is boiling. Different vegetables require different blanching times, and specified times for each vegetable must be observed. Under-blanching is like no blanching at all, and over-blanching, while stopping the enzyme action, will produce soggy, discolored vegetables.
1.Why does the author mention 32 degrees Fahrenheit?
A.To suggest the storage temperature for most foods
B.To identify the freezing point of water
C.To state the correct setting for a freezer
D.To give the temperature for blanching
2.Why does the author use the term expensive mistake in discussing blanching?
A.To state that blanching is expensive but very effective
B.To warn that not blanching will harm the food’s nutritional value
C.To emphasize the importance of blanching only a few items at a time
D.To show that many people waste food by blanching improperly
Most vegetables and some fruits need blanching before they are frozen, and to avoid this step would be an expensive mistake. The result would be a product largely devoid of vitamins and minerals. Proper blanching curtails the enzyme action, which vegetables require during their growth and ripening but which continues after maturation and will lead to decay unless it is almost entirely stopped by blanching. This process is done in two ways, either by plunging vegetables in a large amount of rapidly boiling water for a few minutes or by steaming them. For steam blanching, it is important that timing begin when the water at the bottom of the pot is boiling. Different vegetables require different blanching times, and specified times for each vegetable must be observed. Under-blanching is like no blanching at all, and over-blanching, while stopping the enzyme action, will produce soggy, discolored vegetables.
1.Why does the author mention 32 degrees Fahrenheit?
A.To suggest the storage temperature for most foods
B.To identify the freezing point of water
C.To state the correct setting for a freezer
D.To give the temperature for blanching
2.Why does the author use the term expensive mistake in discussing blanching?
A.To state that blanching is expensive but very effective
B.To warn that not blanching will harm the food’s nutritional value
C.To emphasize the importance of blanching only a few items at a time
D.To show that many people waste food by blanching improperly
【分析解答题】 (in) wArm-BlooDED AnimAls, BoDy tEmpErAturE (ArE) mAintAinED within nArrow (limits) rEgArDlEss oF thE tEmpErAturE oF thE AnimAls’ (surrounDings).
【单选题】 The piano is a stringed musical instrument in which the strings are strike by felt-covered hammers controlled by a board.
【单选题】 The Fourth Amendment to the Constitution of the United States regulates the right of the government to search a citizen's personaland property.
【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.
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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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