embryo proper

例句：

1. 1. The embryo is the first stage of development in a developing organism.
   胚胎是发育生物体的第一个阶段。
2. 2. The study of embryology has led to many breakthroughs in medicine.
   胚胎学的研究在医学上取得了许多突破。
3. 3. The embryonic stage of development is crucial for understanding how an organism grows and functions.
   胚胎发育阶段对于理解一个生物体如何生长和运作至关重要。