考研英语真题材料100篇连载8
<p> <span word="Vaccines">Vaccines</span>：<span word="A">A</span> <span word="new">new</span> <span word="health">health</span> <span word="food">food</span> <span word="GETTING">GETTING</span> <span word="two">two</span> <span word="for">for</span> <span word="the">the</span> <span word="price">price</span> <span word="of">of</span> <span word="one">one</span> <span word="is">is</span> <span word="always">always</span> <span word="a">a</span> <span word="good">good</span> <span word="bargain">bargain</span>. <span word="And">And</span> <span word="according">according</span> <span word="to">to</span> <span word="a">a</span> <span word="paper">paper</span> <span word="in">in</span> <span word="this">this</span> <span word="weeks">weeks</span> <span word="Proceedings">Proceedings</span> <span word="of">of</span> <span word="the">the</span> <span word="National">National</span> <span word="Academy">Academy</span> <span word="of">of</span> <span word="Sciences">Sciences</span>, <span word="that">that</span> <span word="is">is</span> <span word="what">what</span> <span word="Tomonori">Tomonori</span> <span word="Nochi">Nochi</span> <span word="of">of</span> <span word="the">the</span> <span word="University">University</span> <span word="of">of</span> <span word="Tokyo">Tokyo</span> <span word="and">and</span> <span word="his">his</span> <span word="colleagues">colleagues</span> <span word="have">have</span> <span word="done">done</span>. <span word="Using">Using</span> <span word="genetic">genetic</span> <span word="engineering">engineering</span>, <span word="they">they</span> <span word="have">have</span> <span word="overcome">overcome</span> <span word="two">two</span> <span word="of">of</span> <span word="the">the</span> <span word="limitations">limitations</span> <span word="of">of</span> <span word="vaccines">vaccines</span>. <span word="One">One</span> <span word="is">is</span> <span word="that">that</span> <span word="they">they</span> <span word="are">are</span> <span word="heat">heat</span>-<span word="sensitive">sensitive</span> <span word="and">and</span> <span word="thus">thus</span> <span word="have">have</span> <span word="to">to</span> <span word="be">be</span> <span word="transported">transported</span> <span word="along">along</span> <span word="a">a</span> <span word="cold">cold</span> <span word="chain">chain</span> <span word="of">of</span> <span word="refrigerators">refrigerators</span> <span word="to">to</span> <span word="the">the</span> <span word="clinics">clinics</span> <span word="where">where</span> <span word="they">they</span> <span word="are">are</span> <span word="used">used</span>. <span word="The">The</span> <span word="other">other</span> <span word="is">is</span> <span word="that">that</span>, <span word="although">although</span> <span word="they">they</span> <span word="stimulate">stimulate</span> <span word="immune">immune</span> <span word="responses">responses</span> <span word="inside">inside</span> <span word="the">the</span> <span word="body">body</span>, <span word="they">they</span> <span word="often">often</span> <span word="fail">fail</span> <span word="to">to</span> <span word="extend">extend</span> <span word="that">that</span> <span word="protection">protection</span> <span word="to">to</span> <span word="the">the</span> <span word="outside">outside</span>, <span word="where">where</span> <span word="it">it</span> <span word="might">might</span> <span word="prevent">prevent</span> <span word="bacteria">bacteria</span> <span word="and">and</span> <span word="viruses">viruses</span> <span word="getting">getting</span> <span word="inside">inside</span> <span word="in">in</span> <span word="the">the</span> <span word="first">first</span> <span word="place">place</span>.<span word="In">In</span> <span word="this">this</span> <span word="context">context</span>, <span word="the">the</span> <span word="outside">outside</span> <span word="is">is</span> <span word="not">not</span> <span word="the">the</span> <span word="skin">skin</span>: <span word="that">that</span> <span word="is">is</span> <span word="dry">dry</span> <span word="and">and</span> <span word="hostile">hostile</span> <span word="to">to</span> <span word="germs">germs</span>. <span word="It">It</span> <span word="is">is</span> <span word="the">the</span> <span word="damp">damp</span> <span word="and">and</span> <span word="welcoming">welcoming</span> <span word="surface">surface</span> <span word="of">of</span> <span word="places">places</span> <span word="such">such</span> <span word="as">as</span> <span word="the">the</span> <span word="lung">lung</span> <span word="and">and</span> <span word="the">the</span> <span word="gut">gut</span> <span word="that">that</span> <span word="are">are</span> <span word="at">at</span> <span word="risk">risk</span>. <span word="Although">Although</span> <span word="these">these</span> <span word="are">are</span> <span word="casually">casually</span> <span word="called">called</span> <span word="internal">internal</span>, <span word="technically">technically</span> <span word="they">they</span> <span word="are">are</span> <span word="not">not</span>. <span word="Any">Any</span> <span word="nasties">nasties</span> <span word="in">in</span> <span word="the">the</span> <span word="gut">gut</span> <span word="or">or</span> <span word="lungs">lungs</span> <span word="have">have</span> <span word="to">to</span> <span word="cross">cross</span> <span word="the">the</span> <span word="walls">walls</span> <span word="of">of</span> <span word="those">those</span> <span word="organs">organs</span> <span word="before">before</span> <span word="they">they</span> <span word="can">can</span> <span word="multiply">multiply</span> <span word="inside">inside</span> <span word="the">the</span> <span word="body">body</span>. <span word="Dr">Dr</span> <span word="Nochis">Nochis</span> <span word="genetic">genetic</span> <span word="engineering">engineering</span> <span word="involved">involved</span> <span word="growing">growing</span> <span word="the">the</span> <span word="vaccine">vaccine</span> <span word="in">in</span> <span word="rice">rice</span>. <span word="To">To</span> <span word="prove">prove</span> <span word="the">the</span> <span word="principle">principle</span>, <span word="he">he</span> <span word="chose">chose</span> <span word="cholera">cholera</span>, <span word="but">but</span> <span word="it">it</span> <span word="should">should</span> <span word="work">work</span> <span word="with">with</span> <span word="other">other</span> <span word="vaccines">vaccines</span> <span word="as">as</span> <span word="well">well</span>. <span word="With">With</span> <span word="cholera">cholera</span>, <span word="the">the</span> <span word="immune">immune</span> <span word="response">response</span> <span word="is">is</span> <span word="induced">induced</span> <span word="by">by</span> <span word="what">what</span> <span word="is">is</span> <span word="known">known</span> <span word="as">as</span> <span word="the">the</span> <span word="cholera">cholera</span> <span word="toxin">toxin</span> <span word="B">B</span>-<span word="subunit">subunit</span>. <span word="This">This</span> <span word="is">is</span> <span word="a">a</span> <span word="protein">protein</span>, <span word="and">and</span> <span word="Dr">Dr</span> <span word="Nochi">Nochi</span> <span word="took">took</span> <span word="the">the</span> <span word="gene">gene</span> <span word="that">that</span> <span word="encodes">encodes</span> <span word="it">it</span> <span word="and">and</span> <span word="inserted">inserted</span> <span word="that">that</span> <span word="gene">gene</span> <span word="into">into</span> <span word="the">the</span> <span word="genome">genome</span> <span word="of">of</span> <span word="rice">rice</span>. <span word="Next">Next</span> <span word="to">to</span> <span word="the">the</span> <span word="B">B</span>-<span word="subunit">subunit</span> <span word="gene">gene</span> <span word="itself">itself</span>, <span word="he">he</span> <span word="inserted">inserted</span> <span word="a">a</span> <span word="second">second</span> <span word="piece">piece</span> <span word="of">of</span> <span word="DNA">DNA</span> <span word="called">called</span> <span word="a">a</span> <span word="promoter">promoter</span>. <span word="This">This</span>, <span word="as">as</span> <span word="its">its</span> <span word="name">name</span> <span word="suggests">suggests</span>, <span word="promotes">promotes</span> <span word="activity">activity</span> <span word="in">in</span> <span word="an">an</span> <span word="adjacent">adjacent</span> <span word="gene">gene</span>. <span word="Promoters">Promoters</span> <span word="themselves">themselves</span> <span word="are">are</span> <span word="activated">activated</span> <span word="by">by</span> <span word="other">other</span> <span word="molecules">molecules</span>, <span word="and">and</span> <span word="whether">whether</span> <span word="they">they</span> <span word="are">are</span> <span word="switched">switched</span> <span word="on">on</span> <span word="or">or</span> <span word="not">not</span> <span word="depends">depends</span> <span word="on">on</span> <span word="whether">whether</span> <span word="the">the</span> <span word="cell">cell</span> <span word="they">they</span> <span word="are">are</span> <span word="in">in</span> <span word="provides">provides</span> <span word="the">the</span> <span word="necessary">necessary</span> <span word="stimulation">stimulation</span>. <span word="In">In</span> <span word="this">this</span> <span word="case">case</span> <span word="Dr">Dr</span> <span word="Nochi">Nochi</span> <span word="picked">picked</span> <span word="a">a</span> <span word="promoter">promoter</span> <span word="that">that</span> <span word="is">is</span> <span word="active">active</span> <span word="in">in</span> <span word="the">the</span> <span word="tissue">tissue</span> <span word="of">of</span> <span word="rice">rice</span> <span word="grains">grains</span>. <span word="It">It</span> <span word="was">was</span> <span word="then">then</span> <span word="just">just</span> <span word="a">a</span> <span word="question">question</span> <span word="of">of</span> <span word="growing">growing</span> <span word="the">the</span> <span word="rice">rice</span> <span word="and">and</span> <span word="feeding">feeding</span> <span word="the">the</span> <span word="resulting">resulting</span> <span word="grains">grains</span> <span word="to">to</span> <span word="some">some</span> <span word="experimental">experimental</span> <span word="mice">mice</span> <span word="to">to</span> <span word="find">find</span> <span word="out">out</span> <span word="what">what</span> <span word="would">would</span> <span word="happen">happen</span>. <span word="The">The</span> <span word="first">first</span> <span word="thing">thing</span> <span word="that">that</span> <span word="happened">happened</span> <span word="was">was</span> <span word="that">that</span> <span word="the">the</span> <span word="grains">grains</span> <span word="protected">protected</span> <span word="the">the</span> <span word="B">B</span>-<span word="subunit">subunit</span> <span word="from">from</span> <span word="being">being</span> <span word="broken">broken</span> <span word="down">down</span> <span word="in">in</span> <span word="the">the</span> <span word="stomach">stomach</span>, <span word="thus">thus</span> <span word="overcoming">overcoming</span> <span word="one">one</span> <span word="of">of</span> <span word="the">the</span> <span word="regular">regular</span> <span word="bugbears">bugbears</span> <span word="of">of</span> <span word="protein">protein</span>-<span word="based">based</span> <span word="drugs">drugs</span>: <span word="that">that</span> <span word="they">they</span> <span word="cannot">cannot</span> <span word="be">be</span> <span word="given">given</span> <span word="by">by</span> <span word="mouth">mouth</span>, <span word="because">because</span> <span word="they">they</span> <span word="will">will</span> <span word="be">be</span> <span word="digested">digested</span>. <span word="This">This</span> <span word="is">is</span> <span word="a">a</span> <span word="problem">problem</span> <span word="with">with</span> <span word="todays">todays</span> <span word="cholera">cholera</span> <span word="vaccine">vaccine</span> <span word="which">which</span> <span word="is">is</span> <span word="indeed">indeed</span> <span word="taken">taken</span> <span word="by">by</span> <span word="mouth">mouth</span> <span word="and">and</span> <span word="therefore">therefore</span> <span word="affords">affords</span> <span word="poor">poor</span> <span word="protection">protection</span>. <span word="When">When</span> <span word="the">the</span> <span word="B">B</span>-<span word="subunits">subunits</span> <span word="got">got</span> <span word="to">to</span> <span word="the">the</span> <span word="intestines">intestines</span> <span word="they">they</span> <span word="did">did</span> <span word="exactly">exactly</span> <span word="what">what</span> <span word="Dr">Dr</span> <span word="Nochi">Nochi</span> <span word="hoped">hoped</span> <span word="and">and</span> <span word="induced">induced</span> <span word="the">the</span> <span word="production">production</span> <span word="of">of</span> <span word="antibodies">antibodies</span> <span word="and">and</span> <span word="the">the</span> <span word="secretion">secretion</span> <span word="of">of</span> <span word="those">those</span> <span word="antibodies">antibodies</span> <span word="into">into</span> <span word="the">the</span> <span word="mucous">mucous</span> <span word="coating">coating</span> <span word="of">of</span> <span word="the">the</span> <span word="intestinal">intestinal</span> <span word="wall">wall</span>. <span word="Dr">Dr</span> <span word="Nochis">Nochis</span> <span word="mice">mice</span> <span word="really">really</span> <span word="were">were</span> <span word="protected">protected</span>. <span word="When">When</span> <span word="he">he</span> <span word="fed">fed</span> <span word="them">them</span> <span word="cholera">cholera</span> <span word="toxin">toxin</span>, <span word="they">they</span> <span word="did">did</span> <span word="not">not</span> <span word="get">get</span> <span word="sick">sick</span>. <span word="On">On</span> <span word="top">top</span> <span word="of">of</span> <span word="all">all</span> <span word="this">this</span>, <span word="he">he</span> <span word="got">got</span> <span word="as">as</span> <span word="good">good</span> <span word="a">a</span> <span word="response">response</span> <span word="with">with</span> <span word="rice">rice</span> <span word="that">that</span> <span word="had">had</span> <span word="been">been</span> <span word="stored">stored</span> <span word="at">at</span> <span word="room">room</span> <span word="temperature">temperature</span> <span word="for">for</span> 18 <span word="months">months</span> <span word="as">as</span> <span word="he">he</span> <span word="did">did</span> <span word="when">when</span> <span word="he">he</span> <span word="used">used</span> <span word="fresh">fresh</span> <span word="grains">grains</span>. <span word="For">For</span> <span word="a">a</span> <span word="vaccine">vaccine</span> <span word="against">against</span> <span word="a">a</span> <span word="disease">disease</span> <span word="that">that</span> <span word="is">is</span> <span word="found">found</span> <span word="predominantly">predominantly</span> <span word="in">in</span> <span word="poor">poor</span> <span word="countriesplaces">countriesplaces</span> <span word="that">that</span> <span word="tend">tend</span> <span word="to">to</span> <span word="lack">lack</span> <span word="refrigerators">refrigerators</span> <span word="and">and</span> <span word="have">have</span> <span word="only">only</span> <span word="intermittent">intermittent</span> <span word="power">power</span> <span word="to">to</span> <span word="run">run</span> <span word="those">those</span> <span word="that">that</span> <span word="do">do</span> <span word="existthat">existthat</span> <span word="is">is</span> <span word="an">an</span> <span word="enormous">enormous</span> <span word="advance">advance</span>. <span word="If">If</span> <span word="Dr">Dr</span> <span word="Nochis">Nochis</span> <span word="finding">finding</span> <span word="can">can</span> <span word="be">be</span> <span word="translated">translated</span> <span word="into">into</span> <span word="a">a</span> <span word="product">product</span> <span word="that">that</span> <span word="is">is</span> <span word="safe">safe</span> <span word="and">and</span> <span word="effective">effective</span> <span word="for">for</span> <span word="people">people</span>, <span word="it">it</span> <span word="will">will</span> <span word="be">be</span> <span word="a">a</span> <span word="big">big</span> <span word="boost">boost</span> <span word="to">to</span> <span word="the">the</span> <span word="health">health</span> <span word="of">of</span> <span word="the">the</span> <span word="worlds">worlds</span> <span word="poor">poor</span>. </p>
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