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.
Chemicals are used to separate lignin from the cellulose fibers, leaving a pulp mixture that can make stronger papers. Depending on what type of paper is desired, the pulp mixture might need to be bleached to create whiter paper. Papermakers use a variety of chemicals to bleach pulp to the color they want.