the ebb and flow

the ebb and flow (of something/somebody)

​the repeated, often regular, movement from one state to another; the repeated change in level, numbers or amount

the ebb and flow of the seasons

She sat in silence enjoying the ebb and flow of conversation.

He had known her long enough to recognize the ebb and flow of her moods.

the natural ebb and flow of water

We see a constant ebb and flow of jobs.

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