Mr.Smith is the only one of those foreigners who in ChinaA. workB. is workingC. are work

问题补充：

Mr.Smith is the only one of those foreigners who in China．

A. work

B. is working

C. are working

D. had working

答案：

A. work

(答案→)B. is working

C. are working

D. had working

解析：考查定语从句。本题定语从句的先行词是the only on，而不是those foreigners。关系代词who指代先行词the only one在句中做主语，后面使用单数的形式。句意：斯密斯先生是那些外国人中唯一的一个现在在中国工作的人。故B正确。D项的时态错误。