弹钢琴、骑电单车、以每小时2哩速度步行。
Playing the piano , riding a bicycle , walking at a speed of 2 mph .
一个骑着电单车的同行人突然加速靠近我们的车，敲着车窗。
a fellow abolitionist on a moped suddenly sped up to our cruiser and tapped on the window .
骑电单车