囊胚

例句：

1. 1. In the early stages of development, a blastocyst is the first stage of embryonic formation.
   在发育的早期阶段，一个囊胚是胚胎形成的第一个阶段。
2. 2. The study of embryology helps us understand how cells divide and develop into different types of tissues.
   胚胎学的研究帮助我们理解细胞如何分裂并发展成为不同类型的组织。
3. 3. The researchers found that the blastocyst stage was crucial for successful implantation and pregnancy.
   研究人员发现囊胚阶段对于成功植入和怀孕至关重要。