Which of these was one of the four original U.S. cabinet posts under George Washington?

Which of these countries borders Thailand? Oddly, which country's flag was NOT among the four displayed on the summit of Mount Everest on May 29, 1953? Honshu, Kyushu and Shikoku are three of Japan's four main islands. What is the fourth? In December 1944, Marshall, MacArthur, Eisenhower and which air commander became the first U.S. Army five-star generals? Which dentist fought alongside the Earp brothers against the Clanton gang at the O.K. Corral on October 26, 1881? Which of these was one of the four original provinces of Canada at Confederation in 1867? In the complete metamorphosis of most insects, which stage comes between the larva and the adult? Which of these U.S. states is officially called a commonwealth?