It`s very nice__you to help me with my lesson.Aof Bfor Cwith Dto选什么?为什么?

It`s very nice__you to help me with my lesson.Aof Bfor Cwith Dto选什么?为什么?
It`s very nice__you to help me with my lesson.
Aof Bfor Cwith Dto
选什么?为什么?

It`s very nice__you to help me with my lesson.Aof Bfor Cwith Dto选什么?为什么?
A
it's+adj+of/for sb to do sth
of/for究竟用那个看那个adj
e.g It's convenient for you to get there.
这里就不能用of 因为 你不能说you are convenient
但是It' nice of you...就不同
你可以把句子转换成you are nice
就是这样

A
it's + adj + of sb