What's the one part of the human body that doesn't heal quickly (or at all) if injured? Forty to fifty percent of brain injuries occur in vehicular mishaps and even in cases of minor injuries, the long term effects can be permanent and life-altering. For kids, 20% of head injuries result from cycling accidents. Legs, arms, ribs, and many other "parts" can heal, but quite often, brains don't, at least not in the way we want them to.
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