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铜器久置于空气中会和空气中的水蒸气、CO2、O2作用产生“绿锈”,该“绿锈”俗称“铜绿”又称“孔雀石”
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____________,____________;漫江碧透,百舸争流。(《沁园春》)
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Every day Clarke worked hard for a long time ________ he could support his family.
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About a year ago, a couple with three children moved into the apartment next door to me.
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用极限的两边夹逼定理证明lim(1+2的n次方+3的n次方)的n次方分之一=3(n趋向无穷大)
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