(I) Nearly three quarters of the earth is covered with water. (II) Still, people are under the threat of water shortage in most parts of the world. (III) The famine in Africa is the result of several years of drought. (IV) Therefore, scientists see it as an obvious solution to convert sea water in order to increase the fresh water supply. (V) So, they are experimenting with two methods, the well-known distillation process and the freeze-separation process.