你必须要确定你已经准备好了，因为当你向世界上所有还在寻找爱的人宣布它时，你必须确定你在和别人约会时，你不会伤害她。

You have to be sure because when you are going to declare this to all the eligible bachelors and bachelorette in the world, you're sure of it you will not hurt anyone you are dating along the way.

youdao

但是，当你在调查那些一旦出错会造成后果的事情，或者你不确定信息来源，那么你就有充分的理由——甚至是义务——去进一步核实。

But when you're looking into something where being wrong will have consequences, and if you are unsure of the source of the information, you have every reason-even an obligation-to check further.

youdao

当你在超市把东西堆到柜台上的时候，收银员不会问你：“你真的确定想要买下这些东西么？”

The supermarket clerk does not ask, "do you really want to buy these?" when you place groceries on the register belt.

youdao

Then for any time t, you plug in the time t and you will get the location.

那么在任何时刻 t,当你代入 t 的值,就可以确定位移

耶鲁公开课 - 基础物理课程节选