In order to survive in its environment, a single-celled organism uses a contractile
vacuole to remove excess water that diffuses into its cell. Another species, a hydra,
also excretes excess water. Both processes involve the use of energy.
Based on this information, state whether these two organisms live in fresh water or
salt water. Support your answer.

im not in connections yet but i might can you some questions. what grade are you in?

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 : )