Doctors do not yet know why this is true.

VOA: special.2010.06.15

All right, if this is purely a test of, if this is true do this otherwise I don't care, I don't need the ELSE clause in there to identify it. All right?

好，如果这真是一个测验，用来测试如果是真的那么进行一些操作,否则的话我不在乎，那么我不需要ELSE语句,来进行声明了对不对？

麻省理工公开课 - 计算机科学及编程导论课程节选

So if this is true do something else, true otherwise test and see if this is true, do something else, as many as I like followed by the end.

因此如果结果为true那么做一些操作，否则的话再看看这个表达式的值是不是，如果是的话做另外一些操作，我想要多少后面就可以跟多少。

麻省理工公开课 - 计算机科学及编程导论课程节选

You can say if this is true, then go and do the following pieces of code or puzzle pieces that are inside this part of the block, else go ahead and do these that are down here.

你可以说如果条件成立，执行下面的代码段,或板块中的拼图，否则跳过去执行这下面的语句。

哈佛公开课 - 计算机科学课程节选

But this is also true of all of Western Europe, which has to do pretty much with the abolition of farmers and I just don't think it's right for me to pass without mentioning the significance.

西欧的情况亦如此,这与农奴制的废除有很大关系,我个人觉得如果不提一下其重要性,那是我的失职

耶鲁公开课 - 古希腊历史简介课程节选

If you wanted something, and this is still true in France today, it doesn't do any good to go to the local notable, like you did in the eighteenth century and say, "hey,monsieur,the little guy, it would be great if we had a school."

如果你想要什么东西,这在今天的法国仍然是事实,去当地的贵族那里绝无收获,就像是你在十八世纪的时候说,"嘿,小子,如果我有一所学校就再好不过了"

耶鲁公开课 - 1871年后的法国课程节选

So, the point is whenever you have derivatives with something over dt, do not hesitate to cancel the dts This will be actually true as long as both quantities are vanishingly small.

关键在于,只要你推出的式子分母上有dt,不要犹豫,直接约掉,这个式子只在,两遍都是无穷小的情况下成立

耶鲁公开课 - 基础物理课程节选

If something is true do this, else something is true, do that.

如果某些条件是真的，就做这件事，否则另外一些条件为真的话就做另外一件事。

哈佛公开课 - 计算机科学课程节选