cotyledons turn yellow

例句：

1. 1.The plant's cotyledons are the first to emerge from the soil.
   植物的胚轴是第一批从土壤中长出的。
2. 2. Cotyledons play a crucial role in photosynthesis and growth.
   胚轴在光合作用和生长中起着至关重要的作用。
3. 3. The radicle of the cotyledon is the primary part that absorbs water and nutrients.
   胚轴的根是吸收水分和养分的主要部分。