A、In 1959. B、In 1896. C、In 1867. D、In 1872. C

Alaska, which was called Russian America before it was sold to the United States, joined the Union as the forty- ninth state in 1959. (Hawaii was the fiftieth state to join the Union.) Alaska is now the largest of all the 50 states in the U.S.
It was in 1867 that President A. Johnson’s Secretary of State, Seward, bought Alaska from the Russians at a cost of $ 7.2 million. The buying of the huge northern land mass seemed at first something foolishly done. Not only was Alaska difficult to reach, but it was also hard to live in, and it appeared to have no importance in times of war. Besides, there are volcanoes there as Alaska lies on the Pacific "ring of fire." In Alaska, large treeless areas are covered with snow all the year round. For these reasons the buying of Alaska was called "Seward’s Folly" at that time.
However, in 1896 gold was found in Alaska, and people poured into the land quickly. Since then other important natural resources were discovered, including oil. Soon, people changed their thinking about "Seward’s Folly".
But most people visit Alaska in order to see the endless beauty of nature that the northern land discloses to them. For instance, there are about 11,000 islands in Alaska. And in a certain area of Alaska, the sun does not set ice 82 days every year.