Symbol problem of chemical equation Under any circumstances, it is necessary to use ↑

If there is no gas in the reactant and there is gas in the product, use ↑
Precipitation will appear in the double decomposition reaction, only the common precipitation of their own back on the line

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2. In GB2312-80, the coding principle of Chinese characters is: one Chinese character is coded with______ It is represented by a byte A.1 B.2 C.3 D.4
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14. A complete collection of chemical equation symbols As long as it is a chemical equation symbol, it should be complete Sorry, I don't have any wealth
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