to fall slowly, drop by drop.
to move up and down.
to come face-to-face with another person
the high, steep side of a mountain or rock.
to put something over or on something else.
a pile of things, one on top of another.
to arrange things into different types or groups.
to damage something by squeezing it very hard.
break or fall apart into small fragments, especially over a period of time as part of a process of deterioration