Was it his daughter with her work the man spent the whole evening at home?
A. to help, that
B. help, when
C. helping, that
D. helped, which
网友回答
A. to help, that
B. help, when
(答案→)C. helping, that
D. helped, which
解析：考查强调句型。It is...that是强调句型，有一般疑问和特殊疑问句形式，可以强调除谓语外的任何成分。句意“正是帮助他的女儿做作业，那个人才在家了一晚上吗？”spend time doing sth.“花时间做某事”。故选C。