The United States Geological Survey estimates that (as of 2005, the most recent year for which data is available) we withdraw 410 billion gallons of water a day, including both fresh and saline water. Most (80%) of these withdrawals go to thermoelectric power plants (for cooling) and agriculture (for watering crops).
Level 2 is the second darkest hair color level. It is usually used to describe a natural black, and is the natural color of most people who have naturally black hair along with Level 3, soft/light black hair. Refer to the hair color chart. Most drugstore black hair shades are Level 2, medium black. Level 2 hair color is best suited to people whose natural hair color is between Level 2 and Level 3.5.
You use 10 volume for tinting or toning. 20 volume will lift approximately 1-2 levels. 30 volume will lift 2-3 levels. Hair levels are used to classify hair color. A level 1 is the darkest (black, dark brown), level 10 is the lightest (platinum blonde).