Raciborz, Poland - Ethan Bosch (Colorado Springs, Colo./New York AC) has advanced into the semifinals at 84 kg/185 lbs. at the Poland Open on March 13.    Bosch, a five-time U.S. Greco-Roman National Team member, defeated Andrzej Jaworski of Poland 7-1 and Grzegorz Kostka of Poland by fall to advance out of his pool.    In the semifinals, Bosch will meet two-time World champion and 2000 Olympian Ara Abrahamian of Sweden.    Also advancing out of his pool was 2003 U.S. Nationals runner-up Ken Cook (Fremont, Calif./Sunkist Kids) at 74 kg/163 lbs.    Cook defeated Victor Aniskavets of Belarus 8-7 but lost to Michal Flis of Poland 5-3. Because Aniskavets defeated Flis 3-0, Cook advanced out of his pool into the quarterfinals.    In the quarterfinals, Cook lost to 2003 CISM World Military Championships silver medalist Vasilij Rachyba of Ukraine, 7-3.    Two-time U.S. World Team member T.C. Dantzler (Colorado Springs, Colo./New York AC) was the only other American to win a match, defeating Pawel Wiatrowski of Poland 9-2.    Dantzler lost his other pool match to Jerzy Szeibinger of Poland, 4-2 in overtime.