在寒冷的冬天,我们向手上哈气就能使手变暖和,这是通过______改变物体内能的.
向手上哈气时热量会转移到手上,使手的内能增大,温度升高,从而使手变暖和;
故答案为:热传递.
-I can’t go with you today. There will be a test tomorrow.
- ______. Maybe next time.
A.It doesn't matter
B.My pleasure
C.I don’t think so
D.You are welcome
400V柴油发电机组作用?