We are friends since primary school.中为什么用are不用were?是英语九百句里的。

we are the good friends.we know each other since the stone age. We are friends ,just friends We are friends ,just friends we are good friends we are good friends. 《We are friends》歌词 We Are Friends 歌词 We've been friends since way back. We are friends since primary school.中为什么用are不用were?是英语九百句里的。 when we are little ,we are friends . We have been good friends since we met at school. are we just the friends we are good friends翻译 一道英语选择题：We friends since three years ago. We____(be) good friends since we met at school. we've been friends since way back的意思 We've become good friends since last summer.的意思 We first met two years ago,and have been good friends since then.这里的have been是什么时态 是因为we are good friends所以变成have been 一般不是用have become的吗。