问题
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Class A fires are best extinguished by quenching or cooling with _____.
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The type of extinguisher which should be used for an electric fire is ______.A.carbon diox
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This passage mainly discusses ______ .A.the functions of carbon dioxide and waterB.the rol
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Air is composed of ______ gas including hydrogen, oxygen and carbon dioxide.A.variedB.vari
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What is the relationship between carbon dioxide and silicate rocks?A.Silicate rocks are la
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Which of the following scenes contributes the least to the emission of carbon dioxide?A.Wi