This is called the “lookback time”, and it's a cru cial tool for cosmology: by observing very distant objects, we can see the Universe when it was young!

这叫做“回溯间”，是宇宙学一个重要工具：通过观察非常遥远物体，我们可以看到宇宙年轻！

Since four-fifths of the world's potash is traded internationally, the impact of price spikes will be felt in every agricultural region in the world, warns Humphrey Knight of cru, a consultancy.

咨询公司CRU汉弗莱·奈特警告称，由于全球五分之四钾肥都是国际交易，全球所有农业地区都将感受到钾肥价格飙升影响。