单选题 Tom is the only one of the students in his class who ______ studied in China.
A. have B. had C. hadn't D. has

【正确答案】 D
【答案解析】[解析] 在the only one of...结构后面的限制性定语从句中谓语一般用第三人称单数，因为从句中的关系代词代替的是先行词the only one。但在one of the+名词复数后面的限制性定语从句的谓语需用第三人称复数。