A. 1 percent
B. 2.5 percent
C. 7.3 percent
Answer: B -- Only 2.5 percent of water on Earth is fresh water. And 70 percent of that is locked up in polar ice.
5. Though fresh water would seem somewhat precious, Americans use a lot of it every day. On average, what is the approximate daily water use of each household?
A. 25 gallons
B. 50 gallons
C. 300 gallons
Answer: C -- 300 gallons. That's what the U.S. Environmental Protection Agency says. Meanwhile, more than 750 million people (over 10 percent of the world's population) still don't have adequate access to drinking water, according to the United Nations.
6. A lot of the water Americans consume lands on their lawns. What percentage, on average, is used for outdoor purposes?
A. About 10 percent
B. About 30 percent
C. About 60 percent
Answer: B -- About 30 percent of U.S. residential and commercial water goes for outdoor use. And up to 50 percent of that evaporates if you water in the heat of the day, the EPA estimates.
7. Which of the following takes the longest time to break down?
A. Plastic six-pack holder
B. Hard plastic container
C. Disposable diaper
Answer: A -- A plastic six-pack holder takes 450 years to disintegrate. Consider the impact of plastic water bottles, which take as long to biodegrade. The International Bottled Water Association says that in the top 10 global markets alone, people consumed more than 61 billion gallons of bottled water in 2011.
8. Which of the following accounts for the greatest percentage of total waste in the United States?
Answer: A -- Paper is by far the No. 1 item Americans dispose of. But it is also the most recycled material.
9. How much solid waste does the United States produce in one year?