first and foremost的用法

first and foremost的用法？

1.He does a little teaching, but first and foremost he's a writer.他干一点教学，但首要的是写作。

2.I see myself, first and foremost, as a working artist.我首先还是把自己看作一名艺术工作者。

3.It is first and foremost a trade agreement.这首先是一个贸易协议。