单项选择题
A.20minB.30minC.60minD.90min
A.0.01-0.05ppmB.0.05-0.3ppmC.0.3-0.5ppmD.0.5-1.0ppm
A.75%食用酒精消毒B.80%食用酒精消毒C.95%食用酒精消毒D.100%食用酒精消毒
A.上风侧B.左风侧C.右风侧D.下风侧
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