【单选题】Passage 5 Thomas Edison became known as “The Wizard of Menlo Park” in 1877, when he invented the phonograph. Edison’s phonograph allowed people to record sounds and replay them. Though this technology...
【简答题】Sylvan Goldman, an American supermarket owner, invented the shopping trolley ( 购物车 ) in the 1930s. The reasons why he invented the trolley was not just to help shoppers carry their shopping, but also ...