be made of 和 be made up of有什么区别
问题描述：
be made of 和 be made up of有什么区别
桥由石头制成,是用be made of 还是 be made up of
为什么?
请用be made up of举例
答
be made of指看得出原料的,如The bridge is made of stones.be made from指看不出原料的,如Paper is made from wood.be made up of更强调由一组里的某些部分构成,如Our class is made up of 50 students....