amniotic menbrane

例句：

1. 1. The fetus develops within the amniotic sac.
   胎儿在羊膜囊中发育。
2. 2. The amniotic fluid helps to protect the developing baby.
   羊水有助于保护正在发育的婴儿。
3. 3.Amniotic fluid is essential for the growth and development of the fetus.
   羊水对胎儿的生长和发育至关重要。