Recent evidence favors a rival to the long-standing theory that the Americas were colonized 11,000-12,000 years ago by people migrating south from Beringia along a midcontinental ice-free corridor.

最近的证据支持了一个与长期存在的理论对立的观点，该理论认为，在1.1万至1.2万年前，美洲是由从白令海峡沿中大陆无冰走廊向南迁移的人殖民的。

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The concept of square-free coloring was introduced in graph theory by Alon in 2002.

无正方形着色的概念由阿龙在2002年引入图论。

youdao

The multiplier theory only works if you believe there's a fairy passing out free dollars.

只有当你相信有仙女在免费分发钞票时，乘数理论才会起作用。

youdao

This trickle-down theory of free speech is probably premature.

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One piece of evidence in favour of this theory is the growing influence of tax-free retirement plans, which have made it possible for younger workers to channel their savings into mutual funds.

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Every hotel that offers free Wi-Fi, which should be every hotel, could in theory give free unlimited calling to anyplace.

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