In this Thursday, Dec. 12, 2013 photo, Assaf Biderman, co-inventor of the Copenhagen Wheel and Associate Director of the SENSEable City Laboratory at MIT, poses with his invention at Superpedestrian, his venture-backed company in Cambridge, Mass. The Copenhagen Wheel is a human/electric hybrid bicycle engine built into a bicycle's back wheel. Pre-orders for the Copenhagen Wheel are being taken with delivery expected by May 2014. (AP Photo/Stephan Savoia)
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