Each puppy emerges in its own placental membrane, or sac, which must be removed before the puppy can breathe.
Each puppy emerges in its own placental membrane, or sac, which must be removed before the puppy can breathe.
胎衣包裹住犬仔，在犬仔呼吸之前，就要将胎衣去掉。
Each puppy emerges in its own placental membrane, or sac, which must be removed before the puppy can breathe.
胎衣包裹住犬仔，在犬仔呼吸之前，就要将胎衣去掉。