Why do birth control pills contain estrogen?

a. eggs are made of estrogen.
b. women normally have no estrogen in their bodies.
c. sperm use progesterone to fertilize eggs.
d. estrogen controls the ovulation process.

One function of the immune system is to attack the foreign cells to protect the body. in organ translate , the body recongnizes that the new organ is made of foreign cells. wha kind of medicine would you give a patient to increase the chances of transplate success

Which box will not accelerate? 4 newtons 4 newtons 4 newtons 25 kg 4 newtons 15 newtons 10 kg 30 newtons 40 newtons 50 kg 30 newtons 30 newtons

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -