So if burning forests didn't create the K-T boundary soot, what did?

K-T分界线灰烬的不是燃烧的森林，那又是什么呢？

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Then, in 1991, researchers discovered a 120-mile-wide, 1.5-mile-deep crater called Chicxulub in Mexico of the same age as the K-T boundary.

随后，在1991年，研究人员在墨西哥发现了与K-T界限在同年代的一个直径120英里宽，1.5英里深的陨石坑，被称为Chicxulub。

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The Re Os isotope composition is obviously different from the rocks of the continental crust, but similar to the K T boundary sediment, and close to the meteorite.

铁锰结壳的铼-锇同位素组成明显有别于大陆地壳岩石，和K- T界线沉积物相似，接近陨石值。

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It doesn't have to be a real container to contain it It's just an imaginary boundary there.

它不必是,一个真实的容器,只是一个想象的边界。

麻省理工公开课 - 热力学与动力学课程节选

At that point,the gods don't like it because like the Judeo-Christian god, they want to have some boundary between the two,but for them it's very important, because the boundary is far from clear.

这样的话,诸神自然不高兴,就像犹太-基督教中的神灵一样,诸神需要人神之间有一道界限,这对诸神而言是非常重要的,因为界限本身就是模糊不清的

耶鲁公开课 - 古希腊历史简介课程节选

But then because children, according to Freud, don't have a good sense of the boundary between their mind and the world, they think their father can tell that they're plotting to kill him and they figure their father is now angry at them.

但是，据弗洛伊德的理论，由于儿童无法很好地,在心理和现实之间划清界限，即他们认为自己的父亲,能够看出他们在密谋弑父,而且他们还认为父亲非常生他们的气。

耶鲁公开课 - 心理学导论课程节选

The question is one of the most hotly contested in palaeontology and revolves around an apparent gap in the fossil record immediately prior to the K-T boundary - the distinct layer of geological sediments separating the Cretaceous and Tertiary periods, and associated with a massive asteroid impact and global extinction event.

BBC: Closing the 'three metre gap'

Biology doesn't see the boundary - and the commission is proposing therefore that the same regulations should apply inside and outside the demarcation line.

BBC: Fishing's global footprint

"I like to exceed expectations so I probably shouldn't really put a boundary on things, " she said.

BBC: 'New Paula' targets gold in 2012