Books are made paper while paper is mainly made wood.A. of; ofB. from; fromC. of; fromD.

问题补充：

Books are made paper while paper is mainly made wood.

A. of; of

B. from; from

C. of; from

D. from; of

答案：

A. of; of

B. from; from

(答案→)C. of; from

D. from; of

解析：能看出原材料用be made of；不能看出原材料用be made from，故答案选C。