(单词翻译:单击)
听力文本
Researchers say they have discovered how humans got teeth. The researchers are from Uppsala University in Sweden. They say that human teeth "first evolved 400 million years ago". They believe our teeth came from an ancient fish called an acanthothoracid. The researchers studied a fossil of the fish. It was difficult to study because the fish is encased in rock. The researchers had to use the strongest X-ray machine in the world to analyse it. They used the X-ray machine to "digitally dissect" the fish. The researchers discovered that the fish's teeth were amazingly similar to human teeth. The researchers also said humans and 60,000 species of jawed vertebrates living on Earth today come from this fish.
The researchers say the acanthothoracid was one of the earliest jawed vertebrates with teeth ever to live. They were very excited at seeing how similar its teeth were to ours. A co-author of the study, Professor Per Ahlberg, said: "These findings change our whole understanding of the origin of teeth." He commented on the similarity to the fish, saying: "Their jawbones resemble those of bony fish and seem to be directly ancestral to our own. When you grin at the bathroom mirror in the morning, the teeth that grin back at you can trace their origins right back to the first jawed vertebrates." Another researcher said: "Nobody expected to find teeth so deep on the evolutionary tree."
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重点解析
1.It was difficult to study because the fish is encased in rock.
encase 包住
When nuclear fuel is manufactured it is encased in metal cans.
核燃料生产出来后被装在金属罐中。
2.They used the X-ray machine to "digitally dissect" the fish.
dissect 仔细分析
Her latest novel was dissected by the critics.
评论家对她最近出版的一部小说作了详细剖析。
参考翻译
研究人员称他们已经发现了人类是如何长牙的。这些研究人员来自瑞典乌普萨拉大学。他们表示，人类牙齿“首次进化于4亿年前”。他们认为我们的牙齿来自一种被称为acanthothoracid的古老鱼类。研究人员研究了这种鱼的化石。由于鱼被包裹在岩石中，所以很难研究。研究人员不得不利用世界上最强X光机对其进行分析。他们使用X光机对这条鱼进行“数位分析”。研究人员发现这条鱼的牙齿和人类的惊人相似。研究人员还表示，人类以及如今生活在地球上的6万种颌类脊椎动物都来自这种鱼。
研究人员表示，acanthothoracid是有史以来最早的有牙齿的颚脊椎动物之一。看到它的牙齿和我们的牙齿如此相似，他们非常兴奋。该研究的联合作者Per Ahlberg教授表示：“这些发现改变了我们对牙齿起源的全面理解。”他对和鱼的这种相似性进行评论，并表示：“它们的颚骨与多骨鱼的颚骨相似，似乎是我们人类牙齿的祖先。当你早上对着浴室的镜子笑时，对着你笑的牙齿，它们的起源可以追溯到最早的有颚的脊椎动物。”另一名研究人员表示：“没人想到会在进化树这么底层的地方发现牙齿。”
