A.無熱電勢(shì) B.熱電勢(shì)與冷端無關(guān) C.熱電勢(shì)是兩端溫度差 D.熱電勢(shì)隨溫度變化
A.800mm B.500mm C.1000mm D.不確定
A.2 B.4 C.6 D.8