Carefully selecting variables
Following the steps outlined in the procedure

1. dermis

2. chemical

3. urine

4. viruses

5. antibodies

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )

the fossil record provides evidence of a common ancestor to many species.