写作科学, 23 3月中世纪晚期历史的奥秘之一就是为什么维京人在15世纪初离开格陵兰岛南部.尽管普遍的看法是由于气温下降，但一项新的研究实际上 ...

As soon as the Greenland Vikings found something that filled the bill closer to home – walrus and narwhal ivory from Disko Bay on Greenland’s north-west coast – they shut the Newfoundland base down ...