![EPA uses alternative fuel cars and buses vehicles nationwide to reduce emissions.](https://webarchive.library.unt.edu/web/20130216030233im_/http://www.free.ed.gov/images/resources/earthday.jpg)
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EarthDay.gov celebrates Earth Day, April 22. Choose 5 actions you'll take to protect the environment...
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![Two little girls plant a tree](https://webarchive.library.unt.edu/web/20130216030233im_/http://www.free.ed.gov/images/resources/neew.jpg)
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![](https://webarchive.library.unt.edu/web/20130216030233im_/http://www.free.ed.gov/images/resources/sci360.jpg)
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Science360 for iPad provides easy access to engaging science and engineering images and video from around the...
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![The City of Washington Birds-Eye view from the Potomac – looking North. 1892](https://webarchive.library.unt.edu/web/20130216030233im_/http://www.free.ed.gov/images/resources/zoom.jpg)
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Zoom into Maps offers hundreds of historical maps -- maps showing European exploration of the Americas...
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