embryonic

科学家们正在研究胚胎发育的早期阶段。

Scientists are studying the ___embryonic stages of development.

这个创意还处于萌芽阶段，但非常有前景。

The idea is still in its ___embryonic phase, but it looks very promising.

科学家正在研究胚胎组织的发育过程。

Scientists are studying the ___embryonic tissues to understand their development.