Progesterone is a hormone released by the corpus luteum in the ovary. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. It may also be involved in the growth of certain cancers.
I've been following various people's posts about the GRE for 10 months now. Some people don't study at all for the GRE, some study for a weekend, the average is about 2 to 3 months, and some study for a year or more.
Many graduate schools in the United States require GRE results as part of the admissions process. The GRE is a standardized test intended to measure the abilities of all graduates in tasks of general academic nature, regardless of their fields of specialization.