听力文本

Or here's a video that I made as part of my show "Crash Course," talking about World War I:
还有这个视频，是我的节目《速成班》中的一期，讲的是第一次世界大战：
The immediate cause was of course the assassination in Sarajevo of the Austrian Archduke Franz Ferdinand,
直接起因当然是发生在萨拉热窝的刺杀事件，奥地利大公弗朗茨·费迪南遇刺身亡，
on June 28, 1914, by a Bosnian-Serb nationalist named Gavrilo Princip.
发生在1914年6月28日，刺客是塞尔维亚民族主义者加夫里洛·普林西普。
Quick aside: It's worth noting that the first big war of the twentieth century began with an act of terrorism.
说句题外话：二十世纪第一场大战起源于一次恐怖主义行动，真是让人无语。
So Franz Ferdinand wasn't particularly well-liked by his uncle, the emperor Franz Joseph -- now that is a mustache!
弗朗茨·费迪南其实并不怎么讨他叔叔喜欢，他叔叔是弗朗茨·约瑟夫皇帝。就是这位大胡子老兄！
But even so, the assassination led Austria to issue an ultimatum to Serbia,
但尽管如此，此次刺杀事件还是导致奥地利向塞尔维亚发出最后通牒，
whereupon Serbia accepted some, but not all, of Austria's demands, leading Austria to declare war against Serbia.
而塞尔维亚只是满足了奥地利的部分要求，从而导致奥地利向塞尔维亚宣战。
And then Russia, due to its alliance with the Serbs, mobilized its army.
然后塞尔维亚的盟国俄罗斯，开始调遣军队。
Germany, because it had an alliance with Austria, told Russia to stop mobilizing, which Russia failed to do,
奥地利的盟国德国，要求俄罗斯停止调遣军队，俄罗斯当然是拒绝的，
so then Germany mobilized its own army, declared war on Russia, cemented an alliance with the Ottomans,
于是德国也开始调集自己的军队，与奥斯曼土耳其结成同盟，向俄罗斯宣战，
and then declared war on France, because, you know, France.
然后又向法国宣战，法国嘛，你懂的。
And it's not just physics and world history that people are choosing to learn through YouTube.
除了物理和世界历史，人们还可以在YouTube上选择学习其他东西。
Here's a video about abstract mathematics.
下面是一个关于抽象数学的视频。
So you're me, and you're in math class yet again, because they make you go every single day.
假设你是我，你再次来到了数学课堂上，因为数学课每天都有。
And you're learning about, I don't know, the sums of infinite series.
你现在学的，可能是无穷级数求和。

That's a high school topic, right?
是高中的题，对吗？
Which is odd, because it's a cool topic, but they somehow manage to ruin it anyway.
这事儿很怪，因为本来这道题很有趣，但他们（老师）总是有办法把它毁掉。
So I guess that's why they allow infinite series in the curriculum.
我想这就是为什么他们会把无穷级数列入课程吧。
So, in a quite understandable need for distraction,
因为无聊的原因，
you're doodling and thinking more about what the plural of "series" should be than about the topic at hand:
你可能会一边在本子上乱画一边在想，“级数”这个词的复数形式应该是什么，而没有想这道题本身：
"serieses," "seriese," "seriesen," and "serii?"
“serieses,” “seriese,” “seriesen,”还是“serii?”
Or is it that the singular should be changed:
或者单数形式是不规则变化：
one "serie," or "serum," just like the singular of "sheep" should be "shoop."
一个“serie”或者“serum”，就像“sheep”的单数应该是“shoop”。
But the whole concept of things like 1/2 + 1/4 + 1/8 + 1/16 and so on approaches one,
但是这个概念，就像1/2+1/4+1/8+1/16并以此类推，直到无穷接近于1，
is useful if, say, you want to draw a line of elephants, each holding the tail of the next one:
在什么时候有用呢，你想画一排大象，每一只都叼着下一只的尾巴：
normal elephant, young elephant, baby elephant, dog-sized elephant,
普通大象，年轻大象，婴儿大象，像狗那么大的大象，
puppy-sized elephant, all the way down to Mr. Tusks and beyond.
像小狗那么大的大象，一直小到看不见。
Which is at least a tiny bit awesome, because you can get an infinite number of elephants in a line,
这么想还是挺神奇的，因为你可以画无穷多的大象站成一排，
and still have it fit across a single notebook page.
仅仅只需要一张笔记本纸就能画下。

演讲介绍

在线学习就是一场教室革命，但在种类庞杂的信息中，如何利用好这个资源，还需要书呆子来给你讲讲。别瞧不起书呆子，学渣将来都要给人打工。