小立身材短胖，被同学起绰号叫做“武大郎”，小立心里感到特别难过。你想对那些爱给别人起绰号的同学说[ ]

A．人人都有自尊，不要做有损他人人格的事

B．尊重他人要有一颗宽容的心

C．尊重他人要尊重他人的劳动

D．只有做到自尊自爱，才能赢得他人的尊重

It is very kind ______  you to help me with my lessons. It is difficult ______ me to learn them well. [ ]

A. of, of

B. for, of

C. of, for

D. for, for