物体的热能在不借助任何其他物质做传热介质的情况下,高温物体将热量直接向外发射给低温物体的传递方式叫()。
参考答案:热辐射
Letter boxes are much more in the UK than in the USA, where most people have a mailbox
instead. [ ]
A. common
B. normal
C. ordinary
D. usual
试述合同法基本原则的法律意义。