例1：They walked slowly
along
the road.
（他们
沿
公路慢慢⾛。）
例2：I looked
along
the shelves for the book I needed.
（我在书架上
⼀格⼀格
地找我需要的那本书。）
例3：Houses have been built
along
both sides of the river.
（
沿
河两岸已盖起了房屋。）