An electric toothbrush gets power from its base without the help of metal contacts. Find out how this sealed system works in the following podcast from HowStuffWorks.com.
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BrainStuff Classics: Why Are Some Americans Cancelling Columbus Day?
07:16

American Versus British English: What Are Biscuits, Muffins, and Pudding?
09:51

How Do Sunspots Work?
14:22