周而复始

例句：

1. 1. The cycle of life is a beautiful pattern that repeats itself.
   生命的循环是一个美丽的模式，它不断重复。
2. 2. The story of the old man's life was a cycle of hardship and success.
   老人一生的故事是苦难与成功的循环。
3. 3. The sun sets over the horizon, marking the end of another day and the beginning of a new cycle.
   太阳在地平线上落下，标志着又一天的结束和一个新周期的开始。