Which of the following statements about estuaries are true? a. they are the gateway to freshwater breeding grounds of some marine animalsb. they are the breeding grounds for many types of aquatic animalsc. estuaries are resistant to pollution because the constant inflow of freshwater flushes the pollutants out into the ocean. d. they are areas where freshwater streams or rivers merge with the sea

the second type of galaxy is called a barred spiral, which has a thing called a bar straddling the nucleus

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

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 : )