问题补充:
This is the only one of the students the truth.
A. that knows
B. that know
C. who know
D. which knows
答案:
(答案→)A. that knows
B. that know
C. who know
D. which knows
解析:句意:这是唯一一个知道真相的学生。通过分析句子结构,可知这个句子中包含一个定语从句,先行词是one of the students,指人,且one of the students,谓语动词用单数,选A。