The temperature corresponding to the initial calibration line of an ordinary thermometer is () A.0℃ B.0 C.20℃ D. None of the above statements are correct.

According to the needs, the measuring objects of thermometers are very different. The most commonly used thermometers are: laboratory thermometer, which is often used to measure the temperature of general liquid and explore the boiling of water, so the starting scale is often 0℃ and the highest temperature is100℃; Thermometers are used to measure temperature. According to needs, the lowest temperature is generally around -20℃ and the highest temperature is around 50℃. Thermometers generally measure the temperature from 35℃ to 42℃ according to the change of human body temperature. Therefore, the thermometer has no fixed starting scale, but changes according to the scope of use.

So choose D.