blue gold造句怎么写

三个或三以上且后附连词的名词，除最后一项外，都要在彼此之间添加逗号 如： red, white,and blue gold, silver, or copperHeopenedtheletter,readit,andmadeanoteofitscontents. 这里的逗号常称为“连续”逗号。

And this dam is just one of dozens being planned or built in what has been called a "blue gold rush, " an infrastructure spree that is transforming the South American interior.