The follicular phase begins with an increase in follicle-stimulation hormone (FSH), which causes increases in luteinizing hormone (LH) and gonadotropin-releasing hormone (GnRH). Concurrent increases in estrogen levels cause increases in progesterone, stimulating proliferation of the endometrium.
Examples of insulators include plastics, Styrofoam, paper, rubber, glass and dry air. The division of materials into the categories of conductors and insulators is a somewhat artificial division. It is more appropriate to think of materials as being placed somewhere along a continuum.
What is paper ? Paper is an incredibly versatile substance made from naturally occurring plant fibres called cellulose. Originally derived from cloth rags and grasses, paper is now predominantly made with wood (in Europe, non-wood based pulp accounts for just 1.3% of pulp production).