2014考研英语阅读经典试题及答案(15)
<p> <span word="SAMPLE">SAMPLE</span> 15</p><p> [生态学]</p><p> <span word="As">As</span> <span word="Gilbert">Gilbert</span> <span word="White">White</span>, <span word="Darwin">Darwin</span>, <span word="and">and</span> <span word="others">others</span> <span word="observed">observed</span> <span word="long">long</span> <span word="ago">ago</span>, <span word="all">all</span> <span word="species">species</span> <span word="appear">appear</span> <span word="to">to</span> <span word="have">have</span> <span word="the">the</span> <span word="innate">innate</span> <span word="capacity">capacity</span> <span word="to">to</span> <span word="increase">increase</span> <span word="their">their</span> <span word="numbers">numbers</span> <span word="from">from</span> <span word="generation">generation</span> <span word="to">to</span> <span word="generation">generation</span>. <span word="The">The</span> <span word="task">task</span> <span word="for">for</span> <span word="ecologists">ecologists</span> <span word="is">is</span> <span word="to">to</span> <span word="untangle">untangle</span> <span word="the">the</span> <span word="environmental">environmental</span> <span word="and">and</span> <span word="biological">biological</span> <span word="factors">factors</span> <span word="that">that</span> <span word="hold">hold</span> <span word="this">this</span> <span word="intrinsic">intrinsic</span> <span word="capacity">capacity</span> <span word="for">for</span> <span word="population">population</span> <span word="growth">growth</span> <span word="in">in</span> <span word="check">check</span> <span word="over">over</span> <span word="the">the</span> <span word="long">long</span> <span word="run">run</span>. <span word="The">The</span> <span word="great">great</span> <span word="variety">variety</span> <span word="of">of</span> <span word="dynamic">dynamic</span> <span word="behaviors">behaviors</span> <span word="exhibited">exhibited</span> <span word="by">by</span> <span word="different">different</span> <span word="population">population</span> <span word="makes">makes</span> <span word="this">this</span> <span word="task">task</span> <span word="more">more</span> <span word="difficult">difficult</span>: <span word="some">some</span> <span word="populations">populations</span> <span word="remain">remain</span> <span word="roughly">roughly</span> <span word="constant">constant</span> <span word="from">from</span> <span word="year">year</span> <span word="to">to</span> <span word="year">year</span>; <span word="others">others</span> <span word="exhibit">exhibit</span> <span word="regular">regular</span> <span word="cycles">cycles</span> <span word="of">of</span> <span word="abundance">abundance</span> <span word="and">and</span> <span word="scarcity">scarcity</span>; <span word="still">still</span> <span word="others">others</span> <span word="vary">vary</span> <span word="wildly">wildly</span>, <span word="with">with</span> <span word="outbreaks">outbreaks</span> <span word="and">and</span> <span word="crashes">crashes</span> <span word="that">that</span> <span word="are">are</span> <span word="in">in</span> <span word="some">some</span> <span word="cases">cases</span> <span word="plainly">plainly</span> <span word="correlated">correlated</span> <span word="with">with</span> <span word="the">the</span> <span word="weather">weather</span>, <span word="and">and</span> <span word="in">in</span> <span word="other">other</span> <span word="cases">cases</span> <span word="not">not</span>.</p><p> <span word="To">To</span> <span word="impose">impose</span> <span word="some">some</span> <span word="order">order</span> <span word="on">on</span> <span word="this">this</span> <span word="kaleidoscope">kaleidoscope</span> <span word="of">of</span> <span word="patterns">patterns</span>, <span word="one">one</span> <span word="school">school</span> <span word="of">of</span> <span word="thought">thought</span> <span word="proposes">proposes</span> <span word="dividing">dividing</span> <span word="populations">populations</span> <span word="into">into</span> <span word="two">two</span> <span word="groups">groups</span>. <span word="These">These</span> <span word="ecologists">ecologists</span> <span word="posit">posit</span> <span word="that">that</span> <span word="the">the</span> <span word="relatively">relatively</span> <span word="steady">steady</span> <span word="populations">populations</span> <span word="have">have</span> <span word="density">density</span>-<span word="dependent">dependent</span> <span word="growth">growth</span> <span word="parameters">parameters</span>; <span word="that">that</span> <span word="is">is</span>, <span word="rates">rates</span> <span word="of">of</span> <span word="birth">birth</span>, <span word="death">death</span>, <span word="and">and</span> <span word="migration">migration</span> <span word="which">which</span> <span word="depend">depend</span> <span word="strongly">strongly</span> <span word="on">on</span> <span word="population">population</span> <span word="density">density</span>. <span word="The">The</span> <span word="highly">highly</span> <span word="varying">varying</span> <span word="populations">populations</span> <span word="have">have</span> <span word="density">density</span>-<span word="independent">independent</span> <span word="growth">growth</span> <span word="parameters">parameters</span>, <span word="with">with</span> <span word="vital">vital</span> <span word="rates">rates</span> <span word="buffeted">buffeted</span> <span word="by">by</span> <span word="environmental">environmental</span> <span word="events">events</span>; <span word="these">these</span> <span word="rates">rates</span> <span word="fluctuate">fluctuate</span> <span word="in">in</span> <span word="a">a</span> <span word="way">way</span> <span word="that">that</span> <span word="is">is</span> <span word="wholly">wholly</span> <span word="independent">independent</span> <span word="of">of</span> <span word="population">population</span> <span word="density">density</span>.</p><p> <span word="This">This</span> <span word="dichotomy">dichotomy</span> <span word="has">has</span> <span word="its">its</span> <span word="uses">uses</span>, <span word="but">but</span> <span word="it">it</span> <span word="can">can</span> <span word="cause">cause</span> <span word="problems">problems</span> <span word="if">if</span> <span word="taken">taken</span> <span word="too">too</span> <span word="literally">literally</span>. <span word="For">For</span> <span word="one">one</span> <span word="thing">thing</span>, <span word="no">no</span> <span word="population">population</span> <span word="can">can</span> <span word="be">be</span> <span word="driven">driven</span> <span word="entirely">entirely</span> <span word="by">by</span> <span word="density">density</span>-<span word="independent">independent</span> <span word="factors">factors</span> <span word="all">all</span> <span word="the">the</span> <span word="time">time</span>. <span word="No">No</span> <span word="matter">matter</span> <span word="how">how</span> <span word="severely">severely</span> <span word="or">or</span> <span word="unpredictably">unpredictably</span> <span word="birth">birth</span>, <span word="death">death</span>, <span word="and">and</span> <span word="migration">migration</span> <span word="rates">rates</span> <span word="may">may</span> <span word="be">be</span> <span word="fluctuating">fluctuating</span> <span word="around">around</span> <span word="their">their</span> <span word="long">long</span>-<span word="term">term</span> <span word="averages">averages</span>, <span word="if">if</span> <span word="there">there</span> <span word="were">were</span> <span word="no">no</span> <span word="density">density</span>-<span word="dependent">dependent</span> <span word="effects">effects</span>, <span word="the">the</span> <span word="population">population</span> <span word="would">would</span>, <span word="in">in</span> <span word="the">the</span> <span word="long">long</span> <span word="run">run</span>, <span word="either">either</span> <span word="increase">increase</span> <span word="or">or</span> <span word="decrease">decrease</span> <span word="without">without</span> <span word="bound">bound</span> . <span word="Put">Put</span> <span word="another">another</span> <span word="way">way</span>, <span word="it">it</span> <span word="may">may</span> <span word="be">be</span> <span word="that">that</span> <span word="on">on</span> <span word="average">average</span> 99 <span word="percent">percent</span> <span word="of">of</span> <span word="all">all</span> <span word="deaths">deaths</span> <span word="in">in</span> <span word="a">a</span> <span word="population">population</span> <span word="arise">arise</span> <span word="from">from</span> <span word="density">density</span>-<span word="independent">independent</span> <span word="causes">causes</span>, <span word="and">and</span> <span word="only">only</span> <span word="one">one</span> <span word="percent">percent</span> <span word="from">from</span> <span word="factors">factors</span> <span word="varying">varying</span> <span word="with">with</span> <span word="density">density</span>. <span word="The">The</span> <span word="factors">factors</span> <span word="making">making</span> <span word="up">up</span> <span word="the">the</span> <span word="one">one</span> <span word="percent">percent</span> <span word="may">may</span> <span word="seem">seem</span> <span word="unimportant">unimportant</span>, <span word="and">and</span> <span word="their">their</span> <span word="cause">cause</span> <span word="may">may</span> <span word="be">be</span> <span word="correspondingly">correspondingly</span> <span word="hard">hard</span> <span word="to">to</span> <span word="determine">determine</span>. <span word="Yet">Yet</span>, <span word="whether">whether</span> <span word="recognized">recognized</span> <span word="or">or</span> <span word="not">not</span>, <span word="they">they</span> <span word="will">will</span> <span word="usually">usually</span> <span word="determine">determine</span> <span word="the">the</span> <span word="long">long</span>-<span word="term">term</span> <span word="average">average</span> <span word="population">population</span> <span word="density">density</span>.</p>
页:
[1]