问题补充：
The World Bank has warned that rising food prices are pushing people below poverty line (贫困线).
A. millions of
B. million of
C. million
D. millions
答案：
(答案→)A. millions of
B. million of
C. million
D. millions
解析：根据结构，只有millions of 表示成百万上千万的，这种表达方式是正确的，故选A
