cotyledons reach their maximum size

例句：

1. 1.The plant's cotyledons are the first to emerge from the soil.
   植物的胚轴是第一个从土壤中冒出来。
2. 2.Cotyledons are responsible for absorbing water and nutrients from the soil.
   胚轴负责从土壤中吸收水分和养分。
3. 3. In some plants, the cotyledons can be modified into leaves or other structures.
   在一些植物中，胚轴可以转化为叶子或其他结构。