Books are made paper and paper is made wood .A. from; ofB. of ; fromC. of ; of

问题补充：

Books are made paper and paper is made wood .

A. from; ofB. of ; fromC. of ; of

答案：

解析：固定结构be made of和be made from都表示有什么制成，前者表示成品和材料没有发生变化；后者表示成品和材料发生了变化。