preheartshape embryo

例句：

1. 1. The pre-heart-shaped embryo is the first stage of a human being's development.
   预心形胚胎是人类发展的第一个阶段。
2. 2. Researchers have been studying the pre-heart-shaped embryo for decades to understand its growth and development.
   研究人员已经研究预心形胚胎几十年了，以了解其生长和发展。
3. 3.During the pre-heart-shaped embryo stage, scientists are trying to identify the genes that control cell division and differentiation.
   在预心形胚胎阶段，科学家们正在尝试识别控制细胞分裂和分化的基因。