Check all that are the types of fossils we have examined
1. trace
2. crustaceans
3. index
4. body

I believe the answer to your question is 3. Index

Hope this helps ya girl! :)

yes? sounds right, but you didn’t ask a question.

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 : )