Friends are those make you smile always open their hearts to you and encourage you to succ

问题补充：

Friends are those make you smile，always open their hearts to you and encourage you to succeed

A. which

B. what

C. whom

D. who

答案：

A. which

B. what

C. whom

(答案→)D. who

解析：本题考查定语从句。当先行词为those时，表示人的时，在从句中作主语用who，故选D。句意：朋友是让你笑，总是敞开心扉并鼓励你成功的人。