A. 79 percent
B. 45.2 percent
C. 35 percent
Answer: C -- Only 35 percent of people who buy a hybrid once buy one again. With all the praise they receive, isn't it surprising so few drivers buy a second one?
4. About 70 percent of the Earth is covered with water. Only a relatively small amount of it is potentially potable fresh water. How much?
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?