For small，first-degree burns the quickest method to relieve pain is to（）.

A.immerse the burn in cold water

B.administer aspirin

C.apply petroleum jelly

D.apply a bandage to exclude air

两点的温度差与温度较高点的温升之比的百分数称为（）。

A.温差

B.温升

C.相对温升

D.相对温差