The decline in the American Indian languages has historical roots: In the mid-19th century, the US government adopted a policy of Americanizing Indian children by removing them from their homes and culture.

国印第安语言的衰落有其历史根源：在19世纪，国政府采取了国化印第安儿童的政策，即将印第安人的孩子们赶出他们的家园，将他们与其文化隔绝。

They then enter the lungs, and the right lung has three lobes - upper lobe, middle lobe, and lower lobe, and the left lung has just an upper lobe and lower lobe.

然后接着看肺部，右肺有三：上、和下；左肺只有两，即上和下。

Derived from the French word “desservir”, meaning to clear the table, the French were using it to mean last course by the mid-16th century.

“dessert”一词源自法语单词 " desservir" ，意为收拾桌子，在16 世纪，法国人用它来指最后一道菜。

The British explorer Wilfred Thesiger crossed it in the mid-20th century and he said it was named Rub al-Khali or " Empty Quarter" because it's so enormous and so desolate.

英国探险家威尔弗雷德·赛西格在20世纪曾穿越过它，据其称这片沙漠他命名为" Rub al-Khali" 或“ Empty Quarter”，因为它是如此的巨大且荒凉。

And there'll be 800 million of them by the middle of this century.

到本世纪这群人将达到 8 亿。

So Victoria knows a thing or two about rabbits – and said the word 'warren' used in town and village names, is evidence that they've been in the UK since the mid-17th Century.

所以维多利亚知道关于兔子的二三事——而且说村镇名字使用" 养兔场" 这个单词证明了兔子自17世纪以来一直存在于英国。

Pandemic dates to the mid-1600s, when it was used widely for " universal" .

" pandemic" 最早出现是在17世纪，那时候这个词泛用来表示" 全世界的" 。含义。

And by the middle of the nineteenth century the Rapanui had almost disappeared completely!

到19世纪，拉帕努伊人几乎完全消失了！

The Penan's way of life has changed considerably since the middle of the twentieth century.

自二十世纪以来，培南人的生活方式发生了相当大的变化。

If these massive quantities of salt were causing hypertension-induced heart disease; then, people at the time must not have cared much about... sudden death... considering the first report of heart disease didn't occur until the mid-1600s.

假设如此大量的盐在当时也引起了高血压诱发的心脏病的话；那么当时的人们一定不太关心......突然死亡......考虑到关于首例心脏病的报道直到 17 世纪才出现。

It was not until the middle of the 20th century that Oxbridge was accepted gradually.

直到20世纪, “牛桥”一词才逐渐人们所接受。

They were not wrong-and that may have been the mid-century civil-rights movement's greatest strength.

他们没有错，而这可能是二十世纪的民权运动最强大的力量。

They're about the United States of America in the middle of the 19th.

它们是在说十九世纪的利坚合众国。

She's also the namesake of NASA's newest telescope, the Nancy Grace Roman Space Telescope is set to launch sometime in the middle of the 2020s.

她也是国宇航局最新望远镜的名字，南希·格雷斯·罗曼太空望远镜将于20世纪20年代发射。

Extreme heat could continue past the middle of the 21st century.

这种极热天气还可能会持续到21世纪以后。

The Japanese herring fishery collapsed in the middle of the 20th century.

20世纪，日本鲱鱼渔业崩溃。

If humans carry on as they are, some 50 percent of the world's plant and animal species will be probably extinct by the middle of this century, that's the environment bit.

如果人类继续这样下去，到本世纪，世界上大约50%的植物和动物物种可能会灭绝，这是环境问题。

During the mid-Cretaceous period, the world's environment was changing globally.

白垩纪正值全球环境不断变化的时期。

Global water demand is projected to increase by 55% by the middle of the century.

全球水需求预计到本世纪将增加55％。

Back in the mid 1800s, it was unthinkable.

而在十八世纪 这简直难以想象。