One of the most common methods to date volcanic rocks uses potassium (radioactive parent) and argon (stable daughter). Potassium is an element found in many minerals and rocks, and it normally has an atomic mass of 39.
I think it’s eutrophication
it is considered feedback mechanisms because the menstrual cycle only happens when the hormone is released, it causes the target tissues to react, that reaction is the feedback.
An astronomical unit (AU) is the approximate distance from the earth to the sun. The answer is D.
