作者用物理方法和化学方法相结合分离了九个矿区的自然金，效果良好，其纯度一般达99%以上。

The authors adopt the combination of physical and chemical methods to separate native gold in 9 mining areas and good results are achieved. The gold purity is usually up to over 99%.

youdao

youdao

一般来说，早晨似乎没有尽头，因为凯迪达特先生十点来，会一直待到两点。

Generally, the morning seems to have no end, for Mr. Candidate comes at ten and stays till two.

youdao