April 20, 2014 12:00 AM
UPDATED April 18, 2014 07:25 PM
Chemists are developing a technique to recycle astronauts’ waste water into spaceship fuel. http://bit.ly/1oMBWzs
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If you turn on the TV, you're bound to see advertisements for a variety of exercise programs guaranteed to help you get in shape and improve your cardiovascular health. But how much exercise do you really need to be heart-healthy? And what type of exercise is best?
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