问题
单项选择题
He lost all his money. The only thing he could do was to call his wife for help at this moment.
A．being called
B．to be called
C．calling
D．call
答案
参考答案：D
解析：[分析] 结构应用 本句考察的是动词不定式作表语，但因主语中含有do，要省略do。因此选项D为答案。