proembryonal tube

例句：

1. 1. The proembryonal tube is a critical structure in the early development of the embryo.
   胚囊管是胚胎早期发育的关键结构。
2. 2. During fertilization, the proembryonal tube grows to connect the sperm and egg.
   在受精过程中，胚囊管生长以连接精子和卵子。
3. 3. The study of proembryonal tubes has led to new insights into the mechanisms of embryonic development.
   对胚囊管的研究揭示了胚胎发育机制的新见解。