1.But the placenta -- the organ that provides material to the embryo from the mother -- is actually formed from the chorion and allantois membranes of the egg.

但是盘——为母亲提供物质器官——实际是由卵子绒毛和形成。机翻

2.Because, the main membranes of an amniotic egg -- known as the sac, the chorion, and the allantois -- are all present in animals that give birth to live young.

因为，羊卵主要——被称为、绒毛和——都存在于生下活幼仔动物身。机翻