Progesterone and luteinizing hormones act together to stimulate ovulation. Progesterone is a very important hormone in pregnancy and it is very important in thickening the uterus' lining in every month for every female. Luteinizing hormone is important in regulating the menstrual cycle and the production of egg cells.
C. both animals and plants have changed over time
I think it's D: ribosomes and mitochondria. do you go to K12?
The gravity of a black hole is so strong that not even light can escape. Even if a bright star is shining right next to a black hole, you cannot see the black hole. Instead of reflecting the light as other objects do, the black hole just swallows the starlight forever.