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A:
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同学们好！
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tóngxuémen hǎo!
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Hello, class!
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BCD:
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老师好！
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lǎoshī hǎo!
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Hello, teacher!
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A:
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老师先问你们一个问题。会游泳的举手！
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lǎoshī xiān wèn nǐmen yī gè wèntí. huì yóuyǒng de jǔshǒu!
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I've got a question to ask you. Whoever can swim, raise your hand!
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B:
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我会我会！
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wǒ huì wǒ huì!
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I can! I can!
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C:
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我也会！我参加游泳比赛还得过奖呢！
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wǒ yě huì! wǒ cānjiā yóuyǒng bǐsài hái dé guò jiǎng ne!
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I can too! I was in a swim meet and I won!
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A:
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那你们游泳的时候，感觉身体是变轻了还是变重了？
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nà nǐmen yóuyǒng de shíhou, gǎnjué shēntǐ shì biàn qīng le háishì biàn zhòng le?
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Then when you swim, does it feel like your body gets lighter or heavier?
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BCD:
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变轻了！
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biàn qīng le!
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Lighter!
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A:
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那是为什么呢？
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nà shì wèishénme ne?
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Why is that?
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B:
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因为水有浮力！
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yīnwèi shuǐ yǒu fúlì!
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Because water has buoyancy!
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A:
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很好！水有浮力。那么物体受到的浮力大小跟什么有关系呢？
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hěn hǎo! shuǐ yǒu fúlì. nàme wùtǐ shòudào de fúlì dàxiǎo gēn shénme yǒu guānxì ne?
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Very good! Water has buoyancy. The degree of buoyancy exhibited on an object is related to what?
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B:
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跟重力有关！
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gēn zhònglì yǒuguān!
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It's related to gravity!
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C:
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跟水的多少有关！
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gēn shuǐ de duōshao yǒuguān!
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It's related to the amount of water!
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A:
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今天老师带来了几个鸡蛋。你们说鸡蛋放进水里会浮起来，还是沉下去？
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jīntiān lǎoshī dàilái le jǐ ge jīdàn. nǐmen shuō jīdàn fàng jìn shuǐ lǐ huì fú qǐlái, háishì chén xiàqu?
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I've brought in a couple of eggs today. When placed in water, do you think that an egg will float or sink?
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B:
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沉下去!
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chén xiàqu!
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It'll sink!
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C:
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如果鸡蛋很小的话，应该能浮起来。
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rúguǒ jīdàn hěn xiǎo dehuà, yīnggāi néng fú qǐlái.
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If the egg is really small, then it should float.
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D:
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哈哈！我打赌，肯定沉下去。
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hāhā! wǒ dǎdǔ, kěndìng chén xiàqu.
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Haha! I'll bet that it sinks.
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A:
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好，我们来演示一下。
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hǎo, wǒmen lái yǎnshì yīxià.
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Okay, let's have a demonstration.
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B:
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沉下去了！
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chén xiàqu le!
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It sank!
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A:
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那怎么才能让它浮起来呢？
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nà zěnme cáinéng ràng tā fú qǐlái ne?
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Then how can we make it float?
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B:
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加水！
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jiā shuǐ!
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Add water!
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C:
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给它个游泳圈！
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gěi tā gè yóuyǒngquān!
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Give it a swimming tube!
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D:
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哪里有那么小的游泳圈!
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nǎli yǒu nàme xiǎo de yóuyǒngquān!
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Where can we get such a small swimming tube?
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A:
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好，老师这里还有一杯水，我们把鸡蛋放进去试试。
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hǎo, lǎoshī zhèlǐ háiyǒu yī bēi shuǐ, wǒmen bǎ jīdàn fàng jìnqù shìshi.
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Okay, I have a cup of water right here. Let's put the egg in and give it a try.
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B:
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浮起来了，浮起来了！
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fú qǐlái le, fú qǐlái le!
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It floats! It floats!
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C:
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太神奇了，居然浮起来了！这杯是什么水？
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tài shénqí le, jūrán fú qǐlái le! zhè bēi shì shénme shuǐ?
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That's so strange, it floats! What kind of water is that?
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A:
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这杯呀，是盐水。这是为什么呢？
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zhè bēi ya, shì yánshuǐ. zhè shì wèishénme ne?
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This cup is salt water. Why would I use salt water?
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B:
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盐水，那不是把鸡蛋变成咸蛋了？
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yánshuǐ, nà bùshì bǎ jīdàn biànchéng xiándàn le?
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Salt water... does it make the eggs into salted eggs?
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C:
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盐水密度比清水大，所以鸡蛋受到的浮力也大。
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yánshuǐ mìdù bǐ qīngshuǐ dà, suǒyǐ jīdàn shòudào de fúlì yě dà.
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The density of salt water is greater than the density of pure water, so the egg has greater buoyancy.
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A:
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对，很好。物体受到的浮力跟液体的密度有关。世界上最咸的湖叫“死海”，不会游泳的人都能浮在海面上看书……
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duì, hěn hǎo. wùtǐ shòudào de fúlì gēn yètǐ de mìdù yǒuguān. shìjiè shàng zuì xián de hú jiào" Sǐhǎi”, bùhuì yóuyǒng de rén dōu néng fú zài hǎimiàn shàng kànshū……
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That's right. Very good. The buoyancy of a substance has to do with the density of the liquid. The world's saltiest lake is called the “Dead Sea”. Even people who can't swim can float on the surface of the sea and read a book.
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D:
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哈哈，那我这只旱鸭子可以去死海上游泳啦！
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hāhā, nà wǒ zhè zhī hànyāzi kěyǐ qù sǐhǎi shàng yóuyǒng la!
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Haha, then even someone like me who can't swim can go the Dead Sea and go swimming!
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