配有三种可以组合的过滤器，利用石子、沙子、过滤纸将
水进行清洁实验，观查进行过滤净化的过程。
Water goes on quite a journey to reach our taps,safe and ready to drink.One of the many important steps in the process is filtration,which uses layers to sift containments out of the water.The kit here introduces how water gets cleaned by building a simple fildreation system and more...
