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 4 is the hair color level that is represented as dark brown. It is one of the most common natural hair colors and also very commonly found in hair dye. Level 4 is also common in red or...
These numbers refer are codes for the colors achieved through the use of the dye in question. Specifically, the numerals refer to the light-level of the color in question. When gauging haircolor, a scale of 1 to 10 is used to represent the lightness of the color of the hair. 1 is the darkest possible color level and would be a dark, dark brown or black, while a 10 represents the lightest possible color and would be a platinum or pale yellow blonde. The exact color achieved is determined by the lightness level and base colors in the hair dye. Knowing this allows you to know that a level 3 with a red base color would probably be a rich warm color like an auburn or chestnut brown.