小明用质量分数为8%的氯化钠溶液配制质量分数为4%的氯化钠溶液50g．

阅读下面语段，完成后面练习题

    “不违农时，谷不可胜食也；数罟不入洿池，鱼鳖不可胜食也；斧斤以时入山林，材木不可胜用也。谷与鱼鳖不可胜食，材木不可胜用，是使民养生丧死无憾也。养生丧死无憾，王道之始也。

    “五亩之宅，树之以桑，五十者可以衣帛矣。鸡豚狗彘之畜，无失其时，七十者可以食肉矣。百亩之田，勿夺其时，数口之家，可以无饥矣；谨庠序之教，申之以孝悌之义，颁白者不负戴于道路矣。七十者衣帛食肉，黎民不饥不寒，然而不王者，未之有也。

   “狗彘食人食而不知检，涂有饿莩而不知发，人死，则曰：‘非我也，岁也。’是何异于刺人而杀之，曰‘非我也，兵也’?王无罪岁，斯天下之民至焉。”

△ABC的两条高的长度分别为3和6，若第三条高也为整数，则第三条高的长度为____．

C

    This year's winner of the Nobel Prize in Medicine is from Japan. According to his research, cells (细胞) sometimes "eat" themselves to keep healthy. In other words, cells can break down old ones and use the useful parts to make new cells, or to fight off viruses (病毒). This new finding could help scientists fight many diseases.

Small machines

    Three scientists from France, the United Kingdom and the Netherlands (荷兰) won the Nobel Prize in Chemistry for their work on small machines. How small? Well, they are a thousand times thinner than a strand (缕) of hair. We can't see them with only our eyes! This technology will open a whole new world for us. For example, we could make very small robots in the future. A doctor could put them into our body. Like policemen, the robots look for the ill parts in our body, and send the medicine right there.

Super-state

As teachers said in your physics class, most things in the world are in three states: solids (固体), liquids (液体) and gases . But at very low or high temperatures, things can turn into a strange state. For example, break down things to their smallest pieces and we get "atoms" (原子). Like Lego building blocks, atoms usually add up to become a 3-D thing, like a box. But atoms in the strange state don't. They stay together and become a flat thing, like a piece of paper.

    This is a new finding of three British-born scientists. And they won the Nobel Prize in Physics this year. They hope to use things in this strange state to make new materials.

About the Prize

    The Nobel Prize was started by Swedish inventor, Alfred Nobel in 1895. It gives prizes to great science research and the people behind it. Every year in October, the Royal Swedish Academy of Sciences decides who wins. It includes six prizes: chemistry, physics, physiology (生理学) or medicine, peace, literature (文学) and economic. This year each winner gets a medal and prize money of more than 6 million yuan.

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