周期性

例句：

1. 1. The cycle of life is a constant reminder of the passage of time.
   生命的循环是时间流逝的不断提醒。
2. 2. The growth cycle of a plant involves several stages from seed to fruit.
   植物的生长周期包括从种子到果实的几个阶段。
3. 3. The market cycles are influenced by economic factors.
   市场周期受经济因素影响。