amniotic sac造句

1、The amniotic sac breaks and is expelled in the third stage of labor.
在第三产程，羊膜囊破裂并被排出。

2、A protective fluid-filled amniotic sac encloses and cushions the fetus.
充满液体的羊膜包裹并保护胎儿缓和震动。

3、Fluid in the amniotic sac surrounding the fetus also contains fetal DNA.
羊膜中的液体包围这胎儿同样含有胎儿的DNA。