Thomas Alva Edison lit up the world with his invention of the electric light. Without him, the world might still be a dark place. However, the electric light was not his only invention. He also invented the phonograph(留声机), the motion picture camera, and over 1,200 other things. About every two weeks he created something new. Thomas A. Edison was born in Milan, Ohio, on February 11, 1847. His family moved to Port Huron, Michigan, when he was seven years old. Surprisingly, he attended school for only two months. His mother, a former teacher, taught him a few things, but Thomas was mostly self-educated. His natural curiosity(好奇) led him to start experimenting at a young age with electrical and mechanical things at home. When he was 12 years old, he got his first job. He became a newsboy on a train that ran between Port Huron and Detroit. He set up a laboratory in a baggage car of the train so that he could continue his experiments in his spare time. Unfortunately, his first work experience did not end well. Thomas was fired when he accidentally(意外地) set fire to the floor of the baggage car. Thomas then worked for five years as a telegraph operator, but he continued to spend much of his time on the job conducting experiments. He got his first patent(专利) in 1868 for a vote recorder run by electricity. However, the vote recorder was not a success. In 1870, he sold another invention, a stock-ticker, for $40,000. A stock-ticker is a machine that automatically prints stock prices on a tape. He was then able to build his first shop in Newark, New Jersey. Thomas Edison was totally deaf in one ear and hard of hearing in the other, but thought of his deafness as a blessing in many ways. It kept conversations short, so that he could have more time for work. He called himself a 'two-shift man' because he worked 16 out of every 24 hours. Sometimes he worked so intensely that his wife had to remind him to sleep and eat. Thomas Edison died at the age of 84 on October 18, 1931, at his estate in West Orange, New Jersey. He left numerous inventions that improved the quality of life all over the world. Thomas Edison worked ______ hours a day so he called himself a 'two-shift man'.