In this Thursday, Dec. 12, 2013 photo, Ruben Cagnie, a software engineer ponders his thoughts as he works on development of the Copenhagen Wheel, a human/electric hybrid bicycle engine at ... more 
In this Thursday, Dec. 12, 2013 photo, Ruben Cagnie, a software engineer ponders his thoughts as he works on development of the Copenhagen Wheel, a human/electric hybrid bicycle engine at Superpedestrian, the hybrid engine's manufacturer, in Cambridge, Mass. (AP Photo/Stephan Savoia) less 
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Associated Press | Photo By Stephan Savoia
Wed, Dec 18, 2013 5:58 AM EST