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to be piled up; to lie on top of one another
to come one after another; to happen over and over; to pile up (e.g. stress); to accumulate
to overlap (each other); to occur at the same time; to happen simultaneously
書類が机の上に重なっている。
Documents are piled up on the desk.
山々が重なって見える景色が美しい。
The scenery where mountains overlap is beautiful.
休みの日に予定が重なった。
My plans overlapped on my day off.