embedding of ovum

例句：

1. 1. The female bird lays eggs in the nest.
   雌性鸟类在巢中产卵。
2. 2. The scientist studied the development of ovum in the lab.
   科学家在实验室研究了卵细胞的发展。
3. 3. The ovum is the beginning of a new life.
   卵是新生命的开始。