gre阅读练习每日一篇(三十七)
<p> 掌握了<span word="gre">gre</span>阅读里的长难句，到了实战演习的时候了。<span word="gre">gre</span>阅读练习每日一篇帮助<span word="gre">gre</span>考生循序渐进地进行练习和总结。希望<span word="gre">gre</span>考生在进行<span word="gre">gre</span>阅读练习时，也按着考试时候的时间规定自己的练习，这样才能有效果。</p><p> <span word="Geologists">Geologists</span> <span word="have">have</span> <span word="long">long</span> <span word="known">known</span> <span word="that">that</span> <span word="the">the</span> <span word="Earths">Earths</span> <span word="mantle">mantle</span> <span word="is">is</span> <span word="heterogeneous">heterogeneous</span>, <span word="but">but</span> <span word="its">its</span> <span word="spatial">spatial</span> <span word="arrangement">arrangement</span> <span word="remains">remains</span> <span word="unresolvedis">unresolvedis</span> <span word="the">the</span> <span word="mantle">mantle</span> <span word="essentially">essentially</span> <span word="layered">layered</span> <span word="or">or</span> <span word="irregularly">irregularly</span> <span word="heterogeneous">heterogeneous</span>? <span word="The">The</span> <span word="best">best</span> <span word="evidence">evidence</span> <span word="for">for</span> <span word="the">the</span> <span word="layered">layered</span> <span word="mantle">mantle</span> <span word="thesis">thesis</span> <span word="is">is</span> <span word="the">the</span> <span word="well">well</span>-<span word="established">established</span> <span word="fact">fact</span> <span word="that">that</span> <span word="volcanic">volcanic</span> <span word="rocks">rocks</span> <span word="found">found</span> <span word="on">on</span> <span word="oceanic">oceanic</span> <span word="islands">islands</span>, <span word="islands">islands</span> <span word="believed">believed</span> <span word="to">to</span> <span word="result">result</span> <span word="from">from</span> <span word="mantle">mantle</span> <span word="plumes">plumes</span> <span word="arising">arising</span> <span word="from">from</span> <span word="the">the</span> <span word="lower">lower</span> <span word="mantle">mantle</span>, <span word="are">are</span> <span word="composed">composed</span> <span word="of">of</span> <span word="material">material</span> <span word="fundamentally">fundamentally</span> <span word="different">different</span> <span word="from">from</span> <span word="that">that</span> <span word="of">of</span> <span word="the">the</span> <span word="midocean">midocean</span> <span word="ridge">ridge</span> <span word="system">system</span>, <span word="whose">whose</span> <span word="source">source</span>, <span word="most">most</span> <span word="geologists">geologists</span> <span word="contend">contend</span>, <span word="is">is</span> <span word="the">the</span> <span word="upper">upper</span> <span word="mantle">mantle</span>.</p><p> <span word="Some">Some</span> <span word="geologists">geologists</span>, <span word="however">however</span>, <span word="on">on</span> <span word="the">the</span> <span word="basis">basis</span> <span word="of">of</span> <span word="observations">observations</span> <span word="concerning">concerning</span> <span word="mantle">mantle</span> <span word="xenoliths">xenoliths</span>, <span word="argue">argue</span> <span word="that">that</span> <span word="the">the</span> <span word="mantle">mantle</span> <span word="is">is</span> <span word="not">not</span> <span word="layered">layered</span>, <span word="but">but</span> <span word="that">that</span> <span word="heterogeneity">heterogeneity</span> <span word="is">is</span> <span word="created">created</span> <span word="by">by</span> <span word="fluids">fluids</span> <span word="rich">rich</span> <span word="in">in</span> <span word="incompatible">incompatible</span> <span word="elements">elements</span> <span word="percolating">percolating</span> <span word="upward">upward</span> <span word="and">and</span> <span word="transforming">transforming</span> <span word="portions">portions</span> <span word="of">of</span> <span word="the">the</span> <span word="upper">upper</span> <span word="mantle">mantle</span> <span word="irregularly">irregularly</span>, <span word="according">according</span> <span word="to">to</span> <span word="the">the</span> <span word="vagaries">vagaries</span> <span word="of">of</span> <span word="the">the</span> <span word="fluids">fluids</span> <span word="pathways">pathways</span>. <span word="We">We</span> <span word="believe">believe</span>, <span word="perhaps">perhaps</span> <span word="unimaginatively">unimaginatively</span>, <span word="that">that</span> <span word="this">this</span> <span word="debate">debate</span> <span word="can">can</span> <span word="be">be</span> <span word="resolved">resolved</span> <span word="through">through</span> <span word="further">further</span> <span word="study">study</span>, <span word="and">and</span> <span word="that">that</span> <span word="the">the</span> <span word="underexplored">underexplored</span> <span word="midocean">midocean</span> <span word="ridge">ridge</span> <span word="system">system</span> <span word="is">is</span> <span word="the">the</span> <span word="key">key</span>.</p><p> 17. <span word="Which">Which</span> <span word="of">of</span> <span word="the">the</span> <span word="following">following</span> <span word="best">best</span> <span word="expresses">expresses</span> <span word="the">the</span> <span word="main">main</span> <span word="idea">idea</span> <span word="of">of</span> <span word="the">the</span> <span word="passage">passage</span>?</p><p> <span word="Current">Current</span> <span word="theories">theories</span> <span word="regarding">regarding</span> <span word="the">the</span> <span word="structure">structure</span> <span word="of">of</span> <span word="the">the</span> <span word="Earths">Earths</span> <span word="mantle">mantle</span> <span word="cannot">cannot</span> <span word="account">account</span> <span word="for">for</span> <span word="new">new</span> <span word="discoveries">discoveries</span> <span word="regarding">regarding</span> <span word="the">the</span> <span word="composition">composition</span> <span word="of">of</span> <span word="mantle">mantle</span> <span word="xenoliths">xenoliths</span>.</p>
页:
[1]