The bronze medals are largely copper because burnished bronze and gold are similar in color, and the mint did not want any confusion as to which medal an athlete receives.

VOA: standard.2010.02.16

So, hopefully, if you were to go back and look you could see that this is, in fact, copper.

因此，我希望大家如果回去再看一遍,这个题目的话，能够知道这是铜原子。

麻省理工公开课 - 化学原理课程节选

So, that's actually the electron configuration we have when we're talking about copper and some other exceptions in the periodic table that you're going to be looking at.

因此，这才是铜原子真正的电子排布,而且我们在元素周期表中,会看到与铜原子类似的,其他例外的情况。

麻省理工公开课 - 化学原理课程节选

The company's output of iron ore, as well as copper, zinc and nickel, surged in the last three months of 2009 because of strong demand from Chinese carmakers and construction companies.

VOA: standard.2010.01.21