"Riding a bike" 是指骑自行车。这个短语的来源可能源自于英语中表示骑马的 "riding"，并将其应用于骑自行车的场景。
例句:
I love riding my bike through the park on a sunny day.
He decided to start riding his bike to work instead of driving.
She's been riding her bike for hours, she must be exhausted.
翻译:
我喜欢在阳光灿烂的日子里骑自行车穿过公园。
他决定开始骑自行车上班，而不是开车。
她已经骑自行车骑了几个小时了，一定很累了。