蝉发音的秘密
<p>蝉为么会发音，对我来说一直是个谜。为了揭开这个秘密，我常常躲在树下悄悄地观察。我发现蝉鸣时，总是“挺胸”、“翘尾”。</p><p><span word="Why">Why</span> <span word="cicadas">cicadas</span> <span word="can">can</span> <span word="pronounce">pronounce</span> <span word="has">has</span> <span word="always">always</span> <span word="been">been</span> <span word="a">a</span> <span word="mystery">mystery</span> <span word="to">to</span> <span word="me">me</span>. <span word="In">In</span> <span word="order">order</span> <span word="to">to</span> <span word="uncover">uncover</span> <span word="the">the</span> <span word="secret">secret</span>, <span word="I">I</span> <span word="often">often</span> <span word="hide">hide</span> <span word="under">under</span> <span word="the">the</span> <span word="tree">tree</span> <span word="and">and</span> <span word="observe">observe</span> <span word="it">it</span> <span word="quietly">quietly</span>. <span word="I">I</span> <span word="found">found</span> <span word="that">that</span> <span word="cicadas">cicadas</span> <span word="always">always</span> "<span word="hold">hold</span> <span word="their">their</span> <span word="chests">chests</span> <span word="up">up</span>" <span word="and">and</span> "<span word="raise">raise</span> <span word="their">their</span> <span word="tails">tails</span>" <span word="when">when</span> <span word="they">they</span> <span word="chirp">chirp</span>.</p><p>这是为什么呢？一天，我捉到了一只蝉，进行了观察研究。我摘掉了蝉的翅膀，把它放在地上，它在地上扑打着小翅膀，叫着；我又折断了它针状式的嘴，可它仍然叫着。蝉究竟靠什么发音呢？经过反复观察，我发现这声音好像是从胸部发出来的。于是，我把它捉起来看，发现它凹部的两侧，各有一片鱼鳞似的硬壳，像钳甲一样，里面有一对透明薄膜。蝉呜时，簿膜地回动，我用手轻轻地一扞这个地方，蝉就叫了。我不停地捏，它就不停地叫。我想：这对簿膜就是它发音器吧！我把簿膜刺破，再怎么捏，它也不叫了。后来妈妈告诉我这是蝉的“响板”，是雄蝉特殊发音器。发音膜的肌肉收缩振动，蝉就会发出声音。雌蝉没有“响板”，所以是哑巴。</p><p><span word="Why">Why</span> <span word="is">is</span> <span word="that">that</span>? <span word="One">One</span> <span word="day">day</span>, <span word="I">I</span> <span word="caught">caught</span> <span word="a">a</span> <span word="cicada">cicada</span> <span word="and">and</span> <span word="made">made</span> <span word="an">an</span> <span word="observation">observation</span>. <span word="I">I</span> <span word="took">took</span> <span word="off">off</span> <span word="the">the</span> <span word="wings">wings</span> <span word="of">of</span> <span word="the">the</span> <span word="cicada">cicada</span> <span word="and">and</span> <span word="put">put</span> <span word="it">it</span> <span word="on">on</span> <span word="the">the</span> <span word="ground">ground</span>. <span word="It">It</span> <span word="flapped">flapped</span> <span word="its">its</span> <span word="little">little</span> <span word="wings">wings</span> <span word="on">on</span> <span word="the">the</span> <span word="ground">ground</span> <span word="and">and</span> <span word="cried">cried</span>. <span word="I">I</span> <span word="broke">broke</span> <span word="its">its</span> <span word="needle">needle</span> <span word="like">like</span> <span word="mouth">mouth</span> <span word="again">again</span>, <span word="but">but</span> <span word="it">it</span> <span word="still">still</span> <span word="cried">cried</span>. <span word="What">What</span> <span word="pronunciation">pronunciation</span> <span word="does">does</span> <span word="cicada">cicada</span> <span word="depend">depend</span> <span word="on">on</span>? <span word="After">After</span> <span word="repeated">repeated</span> <span word="observation">observation</span>, <span word="I">I</span> <span word="found">found</span> <span word="that">that</span> <span word="the">the</span> <span word="sound">sound</span> <span word="seemed">seemed</span> <span word="to">to</span> <span word="come">come</span> <span word="from">from</span> <span word="the">the</span> <span word="chest">chest</span>. <span word="So">So</span> <span word="I">I</span> <span word="caught">caught</span> <span word="it">it</span> <span word="up">up</span> <span word="and">and</span> <span word="saw">saw</span> <span word="that">that</span> <span word="on">on</span> <span word="both">both</span> <span word="sides">sides</span> <span word="of">of</span> <span word="its">its</span> <span word="concave">concave</span>, <span word="there">there</span> <span word="was">was</span> <span word="a">a</span> <span word="hard">hard</span> <span word="shell">shell</span> <span word="like">like</span> <span word="a">a</span> <span word="fish">fish</span> <span word="scale">scale</span>, <span word="like">like</span> <span word="a">a</span> <span word="pair">pair</span> <span word="of">of</span> <span word="Tongjia">Tongjia</span>, <span word="with">with</span> <span word="a">a</span> <span word="pair">pair</span> <span word="of">of</span> <span word="transparent">transparent</span> <span word="films">films</span> <span word="inside">inside</span>. <span word="When">When</span> <span word="the">the</span> <span word="cicada">cicada</span> <span word="whines">whines</span>, <span word="it">it</span> <span word="moves">moves</span> <span word="in">in</span> <span word="a">a</span> <span word="thin">thin</span> <span word="film">film</span>. <span word="I">I</span> <span word="use">use</span> <span word="my">my</span> <span word="hand">hand</span> <span word="to">to</span> <span word="gently">gently</span> <span word="shake">shake</span> <span word="this">this</span> <span word="place">place</span>, <span word="and">and</span> <span word="the">the</span> <span word="cicada">cicada</span> <span word="calls">calls</span>. <span word="I">I</span> <span word="kept">kept</span> <span word="pinching">pinching</span>, <span word="and">and</span> <span word="it">it</span> <span word="kept">kept</span> <span word="barking">barking</span>. <span word="I">I</span> <span word="think">think</span>: <span word="this">this</span> <span word="pair">pair</span> <span word="of">of</span> <span word="film">film</span> <span word="is">is</span> <span word="its">its</span> <span word="pronunciation">pronunciation</span> <span word="device">device</span>! <span word="I">I</span> <span word="pricked">pricked</span> <span word="the">the</span> <span word="film">film</span>. <span word="No">No</span> <span word="matter">matter</span> <span word="how">how</span> <span word="I">I</span> <span word="pinched">pinched</span> <span word="it">it</span>, <span word="it">it</span> <span word="wouldn">wouldn</span>'<span word="t">t</span> <span word="scream">scream</span>. <span word="Later">Later</span>, <span word="my">my</span> <span word="mother">mother</span> <span word="told">told</span> <span word="me">me</span> <span word="that">that</span> <span word="this">this</span> <span word="is">is</span> <span word="the">the</span> "<span word="soundboard">soundboard</span>" <span word="of">of</span> <span word="cicadas">cicadas</span>, <span word="a">a</span> <span word="male">male</span> <span word="cicada">cicada</span> <span word="special">special</span> <span word="pronunciation">pronunciation</span> <span word="device">device</span>. <span word="The">The</span> <span word="muscles">muscles</span> <span word="of">of</span> <span word="the">the</span> <span word="vocal">vocal</span> <span word="membrane">membrane</span> <span word="contract">contract</span> <span word="and">and</span> <span word="vibrate">vibrate</span>, <span word="and">and</span> <span word="cicadas">cicadas</span> <span word="make">make</span> <span word="sounds">sounds</span>. <span word="Female">Female</span> <span word="cicadas">cicadas</span> <span word="are">are</span> <span word="mute">mute</span> <span word="because">because</span> <span word="they">they</span> <span word="don">don</span>'<span word="t">t</span> <span word="have">have</span> <span word="a">a</span> <span word="soundboard">soundboard</span>.</p>
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