外胚层

例句：

1. 1. The embryonic development of the chicken begins with the formation of the ectoderm, which is the outermostlayer of the egg.
   鸡的胚胎发育始于外胚层的形成，这是鸡蛋最外层的组织。
2. 2.In plants, the outer epidermis is responsible for photosynthesis and is often referred to as the "skin" of the plant.
   在植物中，外胚层负责光合作用，通常被称为植物的“皮肤”。
3. 3. The outer layer of the skin provides protection from the environment and can be easily removed for medical reasons.
   皮肤的外层提供了对环境的保护，并且可以容易地移除用于医疗原因。