问题
问答题 简答题
测定挥发分的原理是什么？
答案
参考答案：
煤在900℃＋10℃的温度下，隔绝空气加热10分钟，其中有机物质和一部分矿物质热解成为气体，包括常温下生成的液体逸出，使质量减少，以失去的质量占煤样的百分率，减去煤样的水分后即为挥发分。
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测定挥发分的原理是什么？
参考答案：
煤在900℃＋10℃的温度下，隔绝空气加热10分钟，其中有机物质和一部分矿物质热解成为气体，包括常温下生成的液体逸出，使质量减少，以失去的质量占煤样的百分率，减去煤样的水分后即为挥发分。
Martin is an American boy. He is eight years old. His parents five years ago and he is now living with his grandmother in New York. One morning, Jimmy, one of his classmates, came to his home with an exercises book in his hand. Jimmy lives in a house not far from Martin's. They often go to school together. "Would you help me with this maths problem?" Jimmy said as soon as he came into the room. "It's too hard for me and I can't work it out." "Let me try, " Martin said. "I it isn't too hard for me. " Martin tried his best but he couldn’t work it out, . "If we had a small computer, all the problems would be for us to do. " Jimmy said. "A small computer. . . , " Martin thought for a minute, then he said, "I've got an idea. We can one in a shop. " "A computer is very , and we don’t have enough money. " "That's OK," said Martin. "We can ask the new president some money. He said he would help anyone in trouble. I' m sure he will help us. He is very rich, you know." So they decided to write a letter to the new president. Soon the letter was finished and they hurried to the post office. In front of the post office stood a small box. They the letter into the box carefully and went home happily. The next morning ,they he post office on their way to school. They found,________, the box was not a post box but trash-box(果皮箱).
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