We look at soil chemistry—for example, how much nitrogen or magnesium there is in the soil in one spot—and we compare it with the chemistry of the soil a short distance away.
我们会观察土壤的化学性质——比如某个地方的土壤里有多少氮或者镁——然后与附近土壤的化学性质作比较。
So I look up the distance — - the mean distance to these various planets — and you see that here in millions of kilometers.
我帮你们查阅了一下-,各大行星到太阳的平均距离-,单位是百万千米。
The researchers found that in the northern sky, the fine-structure constant gets smaller with increasing distance, or as astronomers look farther back in time.
研究人员发现在北方天穹,精细结构常数在越远的地方就越小,或者说天文学家所看到的过去越久远。
There are places to stop along the road to look at the fields and forests down below and far in the distance.
VOA: special.2009.07.20
that's one way to think about it, and there's also another way, and this is the way that your book presents it. If you, in fact, have two of the same atom right next to each other, let's say you have a crystal, or let's say you're talking about a metal, what you can do is just look at the distance between the two nuclei, and split that in 1/2, and take the atomic radius that way.
这只是一种定义的思路,另外还有其它方法,也就是你们课本上的方法,如果你,事实上,有两个相同的原子彼此靠在一起,比如说你有一个晶体,或者说你讨论的是一个金属,你所要做的就是,看看这两个原子核之间的距离,然后将距离除以二,就得到了这个原子的半径。
They do the opposite when we look at things in the distance.
VOA: standard.2010.02.21
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