1, stainless steel. before 1903, steel is not only easy to rust, but also easy to be corroded. Between 1903 and 1912, stainless steel emerged as an outstanding industrial metal. Today, stainless steel has not only used in industry, but also widely used in medical and human body.
2, the automobile. 1913, the United States automobile manufacturer Henry Ford officially opened his car assembly line, reduced costs, improved efficiency, so that the car into the common people's homes, into this century has a decisive impact on a major event.?
3, aircraft. August 14, 1901, the first powered aircraft began to fly. In 1933, the world's first regular airline opened, greatly expanding the space of human activity.
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Nuclear Weapons, 1942: The Atomic Age began in 1942. In order to defeat Axis fascism, the highest authorities in the United States decided to launch the Manhattan Project, aimed at developing atomic weapons. At the end of the year, as part of the Manhattan Project, the first nuclear reactor was built and started operating under a sports facility at the University of Chicago.
On July 16, 1945, a mushroom cloud rose from the Los Alamos Atomic Energy Research Center in New Mexico, U.S.A., and the world's first atomic bomb was detonated. On August 6 and 9 of that year, the U.S. dropped two atomic bombs named "Fat Man" and "Little Boy" on Hiroshima and Nagasaki in Japan. The Japanese emperor then declared unconditional surrender. The atomic bombs seemed to have done much to win World War II, but mankind has lived in the shadow of the dreaded atomic weapons ever since.
Baidu Encyclopedia - 20th Century Inventions