lóudào lǐ chuánlái xiǎo chēlún de shēngyīn, yǒushí shì xiǎopéngyou zài qí huábǎnchē

楼道里传来小车轮的声音，有时是小朋友在骑滑板车。

The sound of small wheels comes from the hallway; sometimes it's children riding scooters