为了明白牙刷在嘴里的作用是什么，我必须想象：谁拥有这张嘴？

And to understand what will be the effect of the toothbrush in the mouth, I must imagine: Who owns this mouth?

youdao

和过去打交道让我感觉太拘束了，就像我写的东西必须是事实，不能虚构，但写与未来有关的东西给了我更多的自由去想象，去创作。

I felt too constrained working with the past, like what I wrote needed to be fact as opposed to fiction, but writing about the future gave me more freedom to imagine, to invent.

youdao

他回答说，我必须避免作出如下的想象，即在舞蹈的不同阶段，操作者分别，个别地放置和移动每个枝节。

His answer was that I must not imagine each limb as being individually positioned and moved by the operator in the various phases of the dance.

youdao

This I must say, this topic ignited my imagination when I was a kid when I thought about it; when I was an athlete.

我必须承认，这个话题点燃了我的想象,当我是孩子时想到它;,当我还是一名运动员时。

哈佛公开课 - 幸福课课程节选

One question is this: Is it really true that in order to think about the perfectly straight, I must have somehow, somewhere at some point come up against, had direct knowledge of, the perfectly straight?

一个问题是,难道真的说,为了想象一条完美的直线,我必须,在某处直接碰到,并直接了解一条完美的直线吗

耶鲁公开课 - 死亡课程节选