实验室里可用高锰酸钾制取氧气。主要实验操作步骤有:①停止加热

实验室里可用高锰酸钾制取氧气。主要实验操作步骤有:①停止加热    ②固定试管   ③将导管从水槽中取出     ④装药品和放棉花    ⑤加热    ⑥收集氧气    

⑦检查装置的气密性。则正确的操作步骤顺序是     

   A.①②③④⑤⑥⑦                     B.⑦⑥⑤④③②①     

 C.⑦④②⑤⑥③①                     D.⑦⑥④②⑤①

答案

C

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