The principle of cross-cutting relationships states that certain features-

of rock is cut across

Explanation:

igneous intrusion is always younger then the rock it cuts across

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 : )

geologic time scale (for gradpoint) =)