Along with rattlesnakes and copperheads, which venomous pit viper is native to the United States?

The jejunum and ileum are two sections of the small intestine. What is the first section? Besides Ecuador and Brazil, which South American country does the equator cross? Which of these sitcoms was a spin-off of "The Mary Tyler Moore Show"? Along with the épée and the sabre, what is the third weapon used in Olympic fencing? Which actor won an Oscar for his role in 1974's "The Godfather Part II"? 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?