A U.S. B-52 strategic bomber has made a rare landing in South Korea, according to the nation's military sources, amid North Korea's ongoing missile and nuclear threats.The bomber landed at an air base in the central South Korean city of Cheongju on Tuesday after participating in joint military exercises held by South Korea and the United States, the sources said.The aircraft also staged a commemorative flight for the six-day Seoul International Aerospace and Defense Exhibition, which started the same day.U.S. forces in South Korea said on Monday that the bomber will arrive in South Korea an…READ FULL ARTICLE