Mary is the only one of the teachers who a little Chinese because she is one of my friends who been to China.
A. know；have
B. knows；has
C. knows；have
D. know；has
网友回答
A. know；have
B. knows；has
(答案→)C. knows；have
D. know；has
解析：C
解析 此句包含了两个定语从句，关系代词都在从句中作主语。关系代词的单复数应与定语从句的先行词的单复数保持一致。第一个从句的先行词是the only one of the teachers，指唯一的老师，从句谓
语动词应用单数形式。第二个定语从句先行词是my friends，表示的是复数概念，所以从句谓语用复数，因此答案为C项。