be made of和be made from用法上有什么区别?

问题描述:

be made of和be made from用法上有什么区别?

be made of表示由成品能看出原材料,也就是物理变化.
例 The table is made of wood.桌子是由木头制成的.
be made from则表示由成品看不出原材料.也就是化学变化.
例 Paper is made from wood.纸是由木头制成的.