The early hypothesis of was based on observations that suggested continents were once joined together. later, the theory of explained why large pieces of earth's surface move around and how many of earth's features form.

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 : )