单选题 Three 36 years ago Daniel Gabriel Fahrenheit made his 37 thermometer in his home town of Danzig (Now Gdansk in Poland). The thermometer was filled with 38 and completely sealed, but it was not much use without some sort of 39 to measure the temperature.
One story 40 that, during the winter of 1708-09, Fahrenheit took a measurement of 0 degrees as the coldest temperature outdoors—which would now read as minus 17.8℃. Five years 41 he used mercury instead of alcohol for his 42 , and made a top reference point by measuring his own body temperature as 90 degrees. Soon afterwards he became a glassblower, 43 allowed him to make thinly blown glass tubes that could be marked up with more points on the scale and so 44 accuracy.
Eventually he took the 45 point of his temperature scale from a reading made in ice, water and salt, and a top point made from the boiling point of water. The scale was recalibrated using 180 degrees between these 46 points and Fahrenheit was able to make much more accurate and more 47 measurements of temperature.
But in 1742 a rival challenged the Fahrenheit scale and 48 superseded it. Anders Celsius, in Sweden, invented a scale of 100 degrees between the freezing and boiling points of water and gradually 49 over many countries. However, the British 50 wedded to Fahrenheit until well into the 20th century.