QUESTION FROM CHRIS: I found it interesting how you said that the word for procrastination did not enter the English language until the 16th century.

问：你说的“拖延”这个词直到16世纪才进入英语语言我觉得很有趣。

youdao

I have found the paradox, that if you love until it hurts, there can be no more hurt, only more love.

我领悟了一个道理，只有你爱至成伤才不会有更多的伤痛，只有满满的爱。

youdao

I used to wander in this world until the day when I found you.

我曾经漫步在这个世界上，直到有一天我发现了你。

youdao

So what actually turns out the reality is that h e 2 does exist, but it exists as the weakest chemical bond known, and it wasn't, in fact, even found to exist until 1993, so I can assure you this is not a bond that you see very often in nature, and it is a very, very weak bond.

实际上He2键是存在的，但它是目前所知的最弱的键，直到1993年它才被发现，所以我可以向你们保证在,自然界你们不可能经常看到它，它是种非常非常弱得键。

麻省理工公开课 - 化学原理课程节选