She is being friendly中being是表示什么意思?is不是be的一种形式吗?为何在这里又用is,又用

First let's compare these two sentences:
1) She is smart,hardworking and friendly.
In this case,"She is friendly" means that she is a friendly person (she is always friendly to other people.Her friendliness is her nature).
2) She is a very aggressive person.She does not treat her coworkers very nicely.But today,she is being friendly to me.
In this case,"She is being friendly" means that she is friendly to me at this moment.But this does not mean she is always friendly to me.She may not be this nice tomorrow.
In short,"She is friendly" = "She is a friendly person." "She is being friendly" = "At this moment,she appears friendly to someone."

being 代表“正在……”或“准备……”，是 进行时 和代表一个过程的意思。

我支持"永远的SES"的说法

be...become 正在“变得”怎么样

这里的being是“变的。。。。”
IS是BE动词的一种，
进行时表示一个过程

这道题目我以前高中考过, 说话者的语气是带着嘲讽的,就是说"她现在倒变的客气起来了嘛'.言下之意就是她以前很不友好的.
英语中常用进行时态来突出说话者当时的语气.例如:youare always being late, 这句话突出了说话者当时不高兴的心情.
祝你好运...

be是is的原形，being在这里是is的动词形式.
表示友好的，和善的friendly是副词，而is后面不能直接跟副词，要用形容词或动词补充，所以being在这里起辅助作用．

同意