free chlorine

例句：

1. 1. The swimming pool is filled with free chlorine to prevent bacterial growth.
   游泳池里充满了自由氯气，以防止细菌生长。
2. 2. The chemical plant uses free chlorine to purify the water.
   化工厂使用自由氯气来净化水。
3. 3.Free chlorine is a powerful disinfectant that can kill bacteria and viruses.
   自由氯是一种强力的消毒剂，可以杀死细菌和病毒。