(来学网)生活饮用水中氟化物的允许浓度为
  • A.
    (来学网)0.5mg/L
  • B.
    (来学网)1.0mg/L
  • C.
    (来学网)1.5mg/L
  • D.
    (来学网)2.0mg/L
  • E.
    (来学网)2.5mg/L