    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.
Early aircraft such as the Wright Flyer were built with wood and fabric. The frame of the Wright Flyer was made from spruce and ash and many surfaces were covered with muslin, a fabric. Most airplanes today are made out of aluminum, a strong, yet lightweight metal. The Ford Tri-Motor, the first passenger plane from 1928, was made out of aluminum. The modern Boeing 747 is an aluminum airplane as well. Other metals, such as steel and titanium, are sometimes used to build aircraft. Steel is heavy though, so not too much is used.