We will be for promises to volunteer to help us solve the puzzling problem.A. whoeverB. a

问题补充：

We will be for promises to volunteer to help us solve the puzzling problem.

A. whoever

B. any one of them

C. those who

D. anyone

答案：

(答案→)A. whoever

B. any one of them

C. those who

D. anyone

解析：本题考查宾语从句。will be是动词，promises是动词，故此处应填连词，且做promises的主语，不可省略，由此可排除b 和d。选项c. those who为定语从句，先行词是those，promises要改为promise。