Exposuretoenvironmentaltobaccosmoke(ETS)-alsocalled“second-handsmoke”and“passivesmoking”containsover2023chemicalsincludingover50knowncarcinogens(致癌物)andmanypoisonousthings.NosafelevelofETSexposu

问题：Exposuretoenvironmentaltobaccosmoke(ETS)-alsocalled“second-handsmoke”and“passivesmoking”containsover2023chemicalsincludingover50knowncarcinogens(致癌物)andmanypoisonousthings.NosafelevelofETSexposu

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丁玉波的回答：

网友采纳　　小题1:D小题2:A小题3:B小题4:B小题5:C