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    Maybe you know floods, earthquakes, sandstorms and so on. But have you heard of typhoons?
    Typhoons are some of the worst storms, usually around the Pacific Ocean and the South China Sea. Most happen in July, August and September.
    How does a typhoon happen? When lots of sea water gets hot in the summer sun, it evaporates （蒸发）into the air. This makes the air hotter. When the air gets warm enough, it starts to move higher up into sky. Then cooler air around it rushes in. It fills the space that is left. After the air gets warmer, it starts to move quickly, making wind. The wind goes in circles（圆圈）and it keeps moving higher in the sky. The warmer the air gets, the quicker the wind moves. And when the wind moves faster than 30 metres a second, a typhoon begins.
    A typhoon has two parts, one is called the “eye”. In the eye, the wind does not move so fast. The other part is the wall of clouds around the eye. Here are the strongest winds and hardest rains.
    Typhoons are very dangerous. In November this year, Typhoon Haiyan killed 5500 people in Philippines. More people are missing.
    What to do when a typhoon hits?
    Stay inside. Close all the windows and stay away from them.
    Try to bring all of your things inside. Strong winds could even blow away your bikes!
    Listen to the radio or TV for important information.
    If you're told to go to a safer place, do it right now.

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    Hello,everybody.Welcome to surf on a new Web site—SCIENCE NEWS FOR KIDS!

    Our goal is to offer timely items of interest to kids,accompanied by suggestions for hands on activities,books, articles,Web resources,and other useful materials.

    Our emphasis is on making the Web site attractive by offering kids opportunities to comment on and grade the subject matter,get ideas for science projects,and try out math puzzles.At the same time,we offer teachers creative ways of using science news in their classrooms.

    The Science News for Kids Web site,supported by several corporations and foundations,strengthens the usefulness of Science News in the middle－school classroom and offers entertaining reading and activities for students interested in science.

    A section of the Science News for Kids Web site is devoted to particular interests.At present,we have six such zones: a weekly brainteaser（难题）for those who enjoy solving and inventing puzzles (PuzzleZone),entertaining science－fiction composition exercises for those interested in writing (SciFiZone),and weekly science short description along with science project ideas and tips (ScienceFairZone).The GameZone contains a small selection of logic and memory games.The TeacherZone has materials,including question sheets related to the feature article of the week,so that teachers can bring science news topics to the classroom.The LabZone features a weekly hands on activity or science project idea.In the future,we might add additional zones,for example,for kids interested in robotics,the environment,computers,math,or veterinary（兽医的）medicine and animals.

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我省文昌市面临大海，纬度低，地理条件优越．经过科学家多年考察论证后，国务院批准在文昌市境内建设国家航天基地．目前该项目正在紧锣密鼓建设中．预见2013年可投入使用．届时，航天器将从海南大地上飞向太空，这对我国空间科学的发展，海南国际旅游岛建设和经济发展起到极大的促进作用．

研究太空特殊条件对生物变异的影响，是空间科学的重要组成部分，请你运用有关知识回答下列问题：

（1）卫星将作物种子带到太空，利用太空特殊条件，最终培育出高产优质新品种，这种育种方法属于____ 育种．

（2）前几年，我国科学家利用“神舟”飞船，对人的大颗粒淋巴细胞NK92进行研究，发现NK92的增殖速率约为地面对照组的12.5倍．由此可见，在太空特殊条件下，NK92的细胞分裂周期明显变____ ．上述研究还发现，NK92中有部分基因的表达发生明显差异．基因表达过程可概括为：（请在横线上填写适当内容．）DNA____ 蛋白质

（3）2008年，我国成功地利用“神舟”七号完成了航天员太空行走计划．由于太空条件特殊，在挑选航天员过程中，对航天员的遗传素质高度重视．研究表明，有些人由于遗传方面的原因，对宇宙射线特别敏感，虽然有宇航服的保护，但一旦受到辐射，还可能会发生DNA分子中碱基对的替换、增添或____ ，从而引起基因内部结构的改变，进而可能发生某些相应的病变． 

人类卷舌与不卷舌的性状受基因控制，R决定能卷舌，r决定不能卷舌，现有一对夫妇，父亲能卷舌（RR），母亲不卷舌（rr），生下的后代基因组成是（    ）

滑雪运动深受人民群众喜爱，某滑雪运动员（可视为质点）由坡道进入竖直面内的圆弧形滑道AB，从滑道的A点滑行到最低点B的过程中，由于摩擦力的存在，运动员的速率不变，则运动员沿AB下滑过程中（   ）