(来学网)氟化自来水的适宜浓度为
  • A.
    (来学网)0.05~0.07mg/L
  • B.
    (来学网)0.7~1.0mg/L
  • C.
    (来学网)0.5mg/L
  • D.
    (来学网)1.5mg/L
  • E.
    (来学网)0.04~0.06mg/L