绒毛膜表层

例句：

1. 1.The embryonic development of the fetus is closely related to the chorion, which is the outermost layer of the placenta.
   胎儿的胚胎发育与胎盘的最外层——羊膜紧密相关。
2. 2. The chorionic villi are responsible for providing nutrients and oxygen to the fetus.
   绒毛膜小凹负责向胎儿提供营养和氧气。
3. 3. The chorionic plate is a thin layer of cells that covers the surface of the placenta.
   绒毛膜板是覆盖胎盘表面的一层薄细胞。