胚胎 (pēi tāi): embryo

Scientists observed the embryo's development under a microscope and found that cell division was much faster than expected.

The doctor told the couple that after a successful embryo transfer, several weeks of observation would still be needed to confirm whether the pregnancy was stable.

The chick embryo inside the egg gradually takes shape at a suitable temperature, and around the twenty-first day it will break out of the shell.

This research used stem cells to cultivate an early embryo model, offering a new way to explore the mysteries of human development.