It is associated with the production of eggs and preparing the uterus for the implantation of fertilised eggs. The menstrual cycle occurs over a period of about 28 days. The changes during the cycle are due to four hormones, progesterone, oestrogen, FSH (follicle stimulating hormone) and LH (luteinising hormone).
Examples include wood and paper. Combustible liquids have a flashpoint at or above 100 degrees F but below 200 degrees F. This definition does not include mixtures containing one or more components with a flashpoint at or above 200 degrees F. This group of liquids can also be identified by class.
For example when wood burns, it must do so in the presence of O2 and a lot of heat is produced: Wood as well as many common items that combust are organic (i.e., they are made up of carbon, hydrogen and oxygen). When organic molecules combust the reaction products are carbon dioxide and water (as well as heat).