Mary is one of the girls who always on time.A. isB. amC. areD. was

问题补充：

Mary is one of the girls who always on time.

A. is

B. am

C. are

D. was

答案：

A. is

B. am

(答案→)C. are

D. was

解析：考查定语从句。one of + 复数名词，作先行词时，定语从句的谓语动词应用复数。句意：玛丽是那些总是按时的女孩中的一个。所以选C。