1. Many municipalities fluoridate their water supplies to help prevent tooth decay.

许多市政府给他们的自来水添加氟化物，以帮助预防蛀牙。

2. Public health organizations recommend fluoridating public water systems to improve dental health.

公共卫生组织推荐给公共自来水系统添加氟化物，以改善口腔健康。