2013年大学英语六级考试阅读的训练题11
<p> <span word="The">The</span> <span word="food">food</span> <span word="irradiation">irradiation</span> <span word="process">process</span> <span word="is">is</span> <span word="a">a</span> <span word="simple">simple</span> <span word="one">one</span>. <span word="The">The</span> <span word="new">new</span> <span word="U">U</span>.<span word="S">S</span>. <span word="plant">plant</span>, <span word="Vindicator">Vindicator</span> <span word="of">of</span> <span word="Florida">Florida</span> <span word="Incorporated">Incorporated</span> <span word="in">in</span> <span word="Mulberry">Mulberry</span>, <span word="Fla">Fla</span>., <span word="uses">uses</span> <span word="a">a</span> <span word="material">material</span> <span word="called">called</span> <span word="cobalt">cobalt</span> 60 <span word="to">to</span> <span word="irradiate">irradiate</span> <span word="food">food</span>. <span word="Cobalt">Cobalt</span> 60 <span word="is">is</span> <span word="radioactive">radioactive</span> <span word="isotope">isotope</span> <span word="of">of</span> <span word="the">the</span> <span word="metallic">metallic</span> <span word="element">element</span> <span word="cobalt">cobalt</span>. <span word="Cobalt">Cobalt</span> 60, <span word="which">which</span> <span word="gives">gives</span> <span word="off">off</span> <span word="radiation">radiation</span> <span word="in">in</span> <span word="the">the</span> <span word="form">form</span> <span word="of">of</span> <span word="gamma">gamma</span> <span word="rays">rays</span>, <span word="is">is</span> <span word="also">also</span> <span word="used">used</span> <span word="for">for</span> <span word="radiation">radiation</span> <span word="therapy">therapy</span> <span word="for">for</span> <span word="cancer">cancer</span> <span word="patients">patients</span> <span word="and">and</span> <span word="for">for</span> <span word="sterilizing">sterilizing</span> <span word="hospital">hospital</span> <span word="equipment">equipment</span>. <span word="The">The</span> <span word="radioactive">radioactive</span> <span word="isotope">isotope</span> <span word="is">is</span> <span word="created">created</span> <span word="by">by</span> <span word="bombarding">bombarding</span> <span word="cobalt">cobalt</span> <span word="with">with</span> <span word="subatomic">subatomic</span> <span word="particles">particles</span> <span word="in">in</span> <span word="a">a</span> <span word="nuclear">nuclear</span> <span word="reactor">reactor</span>. <span word="However">However</span>, <span word="irradiation">irradiation</span> <span word="plants">plants</span> <span word="do">do</span> <span word="not">not</span> <span word="themselves">themselves</span> <span word="contain">contain</span> <span word="nuclear">nuclear</span> <span word="reactors">reactors</span>.</p><p> <span word="In">In</span> <span word="the">the</span> <span word="irradiation">irradiation</span> <span word="plant">plant</span>, <span word="food">food</span> <span word="is">is</span> <span word="exposed">exposed</span> <span word="to">to</span> <span word="thin">thin</span> <span word="rods">rods</span> <span word="of">of</span> <span word="cobalt">cobalt</span> 60. <span word="The">The</span> <span word="rods">rods</span> <span word="give">give</span> <span word="off">off</span> <span word="gamma">gamma</span> <span word="rays">rays</span>, <span word="which">which</span> <span word="disrupt">disrupt</span> <span word="chemical">chemical</span> <span word="processes">processes</span> <span word="in">in</span> <span word="contaminating">contaminating</span> <span word="organisms">organisms</span>. <span word="The">The</span> <span word="disruption">disruption</span> <span word="breaks">breaks</span> <span word="down">down</span> <span word="the">the</span> <span word="cell">cell</span> <span word="walls">walls</span> <span word="of">of</span> <span word="organisms">organisms</span> <span word="or">or</span> <span word="destroys">destroys</span> <span word="their">their</span> <span word="genetic">genetic</span> <span word="material">material</span>. <span word="The">The</span> <span word="dose">dose</span>, <span word="set">set</span> <span word="by">by</span> <span word="the">the</span> <span word="U">U</span>.<span word="S">S</span>. <span word="Food">Food</span> <span word="and">and</span> <span word="Drug">Drug</span> <span word="Administration">Administration</span> , <span word="is">is</span> <span word="enough">enough</span> <span word="to">to</span> <span word="kill">kill</span> <span word="organisms">organisms</span> <span word="on">on</span> <span word="food">food</span>, <span word="but">but</span> <span word="not">not</span> <span word="enough">enough</span> <span word="to">to</span> <span word="produce">produce</span> <span word="significant">significant</span> <span word="changes">changes</span> <span word="in">in</span> <span word="the">the</span> <span word="food">food</span> <span word="itself">itself</span>.</p><p> <span word="Although">Although</span> <span word="irradiation">irradiation</span> <span word="slightly">slightly</span> <span word="decreases">decreases</span> <span word="the">the</span> <span word="nutritive">nutritive</span> <span word="value">value</span> <span word="of">of</span> <span word="foods">foods</span>, <span word="the">the</span> <span word="loss">loss</span> <span word="is">is</span> <span word="less">less</span> <span word="than">than</span> <span word="that">that</span> <span word="produced">produced</span> <span word="by">by</span> <span word="some">some</span> <span word="other">other</span> <span word="methods">methods</span> <span word="of">of</span> <span word="food">food</span> <span word="preservation">preservation</span>. <span word="Canning">Canning</span>, <span word="for">for</span> <span word="example">example</span>, <span word="results">results</span> <span word="in">in</span> <span word="a">a</span> <span word="much">much</span> <span word="greater">greater</span> <span word="loss">loss</span> <span word="of">of</span> <span word="nutrients">nutrients</span>.</p><p> <span word="Those">Those</span> <span word="who">who</span> <span word="object">object</span> <span word="to">to</span> <span word="irradiation">irradiation</span> <span word="say">say</span> <span word="that">that</span> <span word="the">the</span> <span word="process">process</span> <span word="may">may</span> <span word="create">create</span> <span word="substances">substances</span> <span word="not">not</span> <span word="found">found</span> <span word="in">in</span> <span word="nonirradiated">nonirradiated</span> <span word="food">food</span>. <span word="Since">Since</span> <span word="the">the</span> 1960<span word="s">s</span> <span word="researchers">researchers</span> <span word="have">have</span> <span word="studied">studied</span> <span word="irradiated">irradiated</span> <span word="food">food</span> <span word="at">at</span> <span word="microscopic">microscopic</span> <span word="levels">levels</span> <span word="to">to</span> <span word="try">try</span> <span word="to">to</span> <span word="find">find</span> <span word="such">such</span> <span word="substances">substances</span>, <span word="called">called</span> <span word="unique">unique</span> <span word="radiolytic">radiolytic</span> <span word="products">products</span>. <span word="After">After</span> <span word="reviewing">reviewing</span> <span word="these">these</span> <span word="studies">studies</span>, <span word="the">the</span> <span word="FDA">FDA</span> <span word="determined">determined</span> <span word="that">that</span> <span word="compounds">compounds</span> <span word="formed">formed</span> <span word="during">during</span> <span word="irradiation">irradiation</span> <span word="are">are</span> <span word="similar">similar</span> <span word="to">to</span> <span word="substance">substance</span> <span word="found">found</span> <span word="in">in</span> <span word="nonirradiated">nonirradiated</span> <span word="foods">foods</span> <span word="and">and</span> <span word="are">are</span> <span word="not">not</span> <span word="dangerous">dangerous</span> <span word="to">to</span> <span word="consume">consume</span>.</p>
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