大象传媒 OS - Rio Olympics 2016: Electric pace-setting bike explained - 大象传媒 Sounds

大象传媒 OS - Rio Olympics 2016: Electric pace-setting bike explained - 大象传媒 Sounds
Rio Olympics 2016: Electric pace-setting bike explained
Many people puzzled by the cyclist in the Olympic velodrome who isn鈥檛 pedalling at all.