    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.
Solar sails could travel to the outermost regions of the solar system faster than ever before. Solar sails are made of ultrathin, highly reflective material. When a photon from the sun hits the mirror-like surface, it bounces off the sail and transfers its momentum.