Question

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

Answer 1

C

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。