当我还是个男孩的时候，我总是认为人们只会买他们需要的东西。

As a boy, I always thought people simply bought whatever they need.

youdao

有时候当我们感到悲伤的时候，我们似乎需要某种精神上的支持。

Sometimes when we are feeling sad, we seem to need some kind of support in spirit.

youdao

我们都知道在我们的生活中谁可以信赖，当我们需要帮助的时候，我们就可以向他们求助。

We know who we can depend on in our lives and turn to them when we need help.

youdao

Another way of saying it is, I can do this stop when I don't need to. All right?

另一种说法是，我能够停下来，当我不需要做的时候，对么？

麻省理工公开课 - 计算机科学及编程导论课程节选

And I have to say when I read those guidelines, I thought that's incredible modest.

不得不说，当我看到这些准则的时候，我觉得需要捐赠的钱款真的不多。

普林斯顿公开课 - 人性课程节选

I have to be really careful when I said, "Add the lengths."

当我说"模长相加"的时候需要非常小心

耶鲁公开课 - 基础物理课程节选