光周期

例句：

1. 1. The plant's growth is affected by the length of its light cycle.
   植物的生长受其光周期长度的影响。
2. 2. This species requires a specific light cycle to thrive.
   这种物种需要特定的光周期才能茁壮成长。
3. 3. The researcher found that the timing of sunrise and sunset had an impact on the plant's growth rate.
   研究者发现日出和日落的时间对植物的生长速率有影响。