prep.
沿，沿着，顺着，循，循着：
Along the river bank there is a hedge.
沿河岸有一排树篱芭。
依照；根据；遵奉：
He thought more and more along that line.
他根据那个原则想了又想。
在…的过程中：
Somewhere along the way I lost my umbrella.
我把雨伞丢失在沿途某处了。
紧贴…的平面(移动)：
The boy was dragging his coat along the gr