    Ð°Ð½ Obstetrician is a physician who has successfully completed specialized education and training in the management of pregnancy, labor, and the puerperium (the t â¦ ime-period directly following childbirth).n Obstetrician specializes in the care and treatment of pregnant women during their pregnancy, labor, delivery and the postpartum period.
Animal skins were used as sails for the earliest boats and rafts. The Egyptians and other ancient people wove reeds together in mats to make sails, but the Egyptians were also the first to make cloth sails as early as 3300 B.C. Great sailors of the Mediterranean region like the Phoenicians sailed under cloth sails.
Boats are commonly made of wood, aluminum, steel, fiberglass or any combination of these materials. Wood is the traditional material used for boat building and is considered aesthetically pleasing. Steel is commonly used on larger vessels, and aluminum is usually found on canoes, skiffs, pleasure craft and fishing power boats that are stored out of the water.