A. AT B. IN C. ON D. OVERIII. ĐỌC ĐOẠN VĂN SAU VÀ CHỌN CÂU TRẢ LỜ...

5. A. at B. in C. on D. overIII. Đọc đoạn văn sau và chọn câu trả lời đúng cho các câu hỏi.The invention of the phonograph happened quite by accident. Thomas Edisonmoved to Menlo Park, New Jersy in 1876, where he established an industrial researchlaboratory. There, Edison was working on a carbon telephone transmitter to improve theexisting Bell telephone system.In that laboratory a year later, Edison invented the phonograph while he was tryingto improve a telegraph repeater. He attached a telephone diaphragm to the needle in thetelegraph repeater; in this way, he was able to reproduce a recording that could be playedback. After he made some improvements to the machine, he tested it. He recited “MaryHad a Little Lamb” into the machine and played his voice back to a very surprisedaudience.