问题补充：
—a volunteer is great.
—I think so. Some of us wantvolunteers for the London Olympics.
A. Being; being
B. To be; being
C. Being; to be
D. To be; to be
答案：
A. Being; being
B. To be; being
(答案→)C. Being; to be
D. To be; to be
解析： C 考查动名词和不定式。动名词可以作主语，谓语用单数形式；“想要做某事”want to do sth.
