It's very nice.中的nice是作状语还是表语,为什么?

It's very nice.中的nice是作状语还是表语,为什么? It's very nice! ( )oh,it's very nice It's very nice ( )you. It's very nice.It's yellow. it’s very nice （是用for 还是 of）you to do 为什么是It's nice talking to you.而不是It's nice to talk to you. It’s nice 中的it指代的对象是? It's very nice是什么意义 It,s very nice of you,中文, it's very nice of you It's very nice ___you to write____me