ecto-entad

例句：

1. 1. The embryonic development of the plant is divided into three main stages: the ectoderm, mesoderm, and endoderm.
   植物胚胎发育分为三个主要阶段：外胚层、中胚层和内胚层。
2. 2. During the formation of the vertebrate nervous system, the ectoderm cells differentiate into neuronsand glial cells.
   在脊椎动物神经系统形成过程中，外胚层细胞分化为神经元和胶质细胞。
3. 3.The study of the ectoderm has led to a better understanding of the role of this layer in animal development.
   对外胚层的研究表明，这一层次在动物发育中的作用更加明确。