— How much does it cost to built the school library?— Fouryuan.A. million ofB. millions o

问题补充：

— How much does it cost to built the school library?

— Fouryuan.

A. million of

B. millions of

C. million

D. Millions

答案：

A. million of

B. millions of

(答案→)C. million

D. Millions

解析：句意：建学校图书馆要花多少钱？四百万。million前面如果有数词修饰，则在后面直接跟million，不加介词of；故选C。