Today, according to UNICEF, at least __1___ billion people lack adequate sanitation, while 1.1 billion people live without clean drinking water period. Water is the key __ 2___ in all of our daily lives no matter where we live, not only for human use, but for energy, industry, agriculture, and __3___. Now if you look at the earth, you’ll notice that over __4__ of our blue planet is water. The problem is only 3% of that water is __5__ water.