bag of water

• 羊膜

bag of water的用法和样例：

例句

1. Amniocentesis is the removal of fluid from the amniotic sac.
   羊膜穿刺术是从羊膜囊抽取羊水的技术。
2. The frequency of chorioamnionitis was compared between groups.
   比较两组中绒毛膜羊膜炎的发生频率。