var killers = new Array(
"How many people lack access to clean drinking water?$$About 500,000%%About 3.6 million^^About 1.2 billion&&About 8.3 million",

"How many of the earth's species are believed to become extinct each year because of human activities?$$560 - 2280 (1.5 - 6 per day)%%4,500 - 18,250 (12.5 - 50 per day)^^9,000 - 36,500 (25 - 100 per day)&&18,000 - 73,000 (50 - 200 per day)",

"What percentage of all species that have ever lived on earth have become extinct?$$99.9% %%10%^^65%&&30%",

"What percentage of the earth's tropical forests have been cleared or damaged?$$About 34% %%About 17%^^About 2.5%&&About 56%",

"What percentage of the sewage in Latin America is treated?$$Less than 2% %%Less than 10%^^More than 50%&&Less than 35%",

"What percentage of environmental spending in the United States is devoted to preventing pollution?$$About 1% %%About 25%^^About 57%&&About 79%",

"What gas in the stratosphere keeps 95% of the sun's harmful ultraviolet radiation from reaching the earth's surface?$$Nitrogen%%Carbon dioxide^^Oxygen&&Ozone",

"What percentage of North America's original temperate deciduous forest land has been cleared?$$About 15% %%About 45%^^About 99%&&About 65%",

"What is the greenhouse effect?$$The amount of solar radiation reaching the earth%%The cooling of the earth's lower atmosphere when heat escapes into space^^The formation of a global sunscreen which keeps about 95% of the sun's harmful ultraviolet radiation from reaching the earth's surface&&Warming of the earth's lower atmosphere because of the presence of heat-trapping gases",

"What greenhouse gas is being emitted to the atmosphere in the largest quantity from human activities?$$Carbon dioxide%%methane^^nitrous oxide&&CFC's",

"What are the most likely initial effects of a warmer world?$$shifts in food-growing regions and water supplies, rising sea levels, and increased biodiversity%%shifts in food-growing regions and water supplies, rising sea levels, and decreased biodiversity^^just a rise in sea levels&&no real adverse effects",

"Which of the following is a way of reducing the threat of global warming?$$maintain current energy efficiency%%increase deforestation^^shift from fossil fuels to renewable energy&&none, we dont need to worry about global warming",

"How long do CFCs stay in the atmosphere?$$A few days - 6 months depending on type%%12 months - 9 years depending on type^^23 - 60 years dependig on type.&&65 - 135 years depending on type",

"What percentage of the earth's enormous supply of water is available to use as usuable fresh water?$$About 10% %%About 46%^^About 32%&&About 0.003%",

"How many people die prematurely every year from drinking contaminated water?$$250,000%%About 10 million^^3.5 million&&1.2 million",

"Which of the following is a more desirable way to deal with hazardous waste?$$incineration%%disposal into streams and sewers^^recycle&&Land disposal",

"How many of the world's 17 major marine fishery zones have been overfished?$$3%%6^^15&&10",

"What percentage of the world's potential food supply is lost to pests?$$About 55% %%About 12%^^About 78%&&About 29%",

"What is the most serious drawback to using chemicals to control pests (especially insects)?$$Kill natutral predators and parasites that prey on the pest species%%Its very expensive^^they dont break down into something harmless after doing its job &&Development of genetic resistance to the chemicals by target pests",

"What percentage of the world's estimated plant species have been evaluated for their medical uses?$$About 50% %%About 2%^^About 70%&&About 16%"
);

var answers = new Array('c','d','a','d','a','a','d','c','d','a','b','c','d','d','b','c','c','a','d','b');