I don't know. What is the postage for U. S. postcards and U. S. letters?

我不知道。发往美国的明信片和信是用什么邮资？

youdao

There is some effort to reopen rare earth mines in the U. S but I don't know how viable they can be for the long run and even with them China's a hard supplier to replace.

美国的确有些稀土矿重开的努力，但我不知道他们是否能够长期开采，即便有他们，中国也是一个很难替代的供应者。

youdao

There is some effort to reopen rare earth mines in the U. S but I don't know how viable they can be for the long run and even with them China's a hard supplier to replace.

美国的确有些稀土矿重开的努力，但我不知道他们是否能够长期开采，即便有他们，中国也是一个很难替代的供应者。

youdao