prevention of scale in boilers

例句：

1. 1.To prevent the spread of disease, wemust wash our hands frequently.
   为了防止疾病的传播，我们必须经常洗手。
2. 2. The company has implementedseveral prevention measures to reduce accidents.
   该公司已经实施了多项预防措施，以减少事故。
3. 3. Prevention is better than cure.
   预防总比治疗好。