It's a fact of life: Together with skin, muscle, bones and organs -- all vital -- the human body is 70% water. Furthering that connection, Pepsi-Cola Company's Aquafina is the best-selling brand of bottled water in U.S. retail channels, nearly tripling industry volume growth in 1999.Beginning this week, in its first national TV ad campaign, Aquafina is reminding consumers: "Every part of your body needs pure water.