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...
The clear hairs appear as gray or white because of the way light is reflected from the hairs. Gray hair color typically occurs naturally as people age (see Aging or achromotrichia, below). For some people this can happen at a very young age (for example, at the age of 10).