On this day, 150 years ago, on February 14, 1875 (January 9, 1875 lunar calendar), Bell received a patent for the telephone. On June 2, 1875, the American Alexander Graham Bell (Alekander Graham) invented the telephone. To this day, the door of 109 Court Road in Boston, USA, is still nailed with a bronze medal engraved: The telephone was born here on June 2, 1875. On February 14, 1876, Bell applied for a patent for the famous device he and Watson had been working on - the telephone. On the same day, another inventor, Gray (1835-1901), also filed a patent application for a similar device with the US Patent Office, only to lose the right to invent the telephone because he was a few hours later than Bell. Bell received the patent certificate for the telephone. On March 10, 1876, Bell accidentally splashed sulfuric acid on his leg while conducting an experiment. He cried out in pain: "Mr. Watson, come and help me!" Unexpectedly, these words were transmitted to the ears of his assistant Watson, who was working in another room, through the telephone during the experiment. This extremely ordinary sentence became the first human voice to be transmitted by telephone and entered the history books.