根据人格理论，我是什么时候开始存在的呢？

When did I begin to exist on the personality theory?

youdao

世界是什么时候开始存在的？

When did the world come into being?

youdao

世界是何时开始存在的?。

When did the world come in to being?

youdao

So iron left to own devices in the atmosphere in the presence of a little bit of water, with the water form iron oxide.

铁在大气中，在存在,少量水的条件下，大气会开始与水结合产生氧化铁。

麻省理工公开课 - 热力学与动力学课程节选

At the end of last class I suggested that from here on I'm going to be assuming that there's no soul.

上一节课的最后,我说了从现在开始,我假定灵魂是不存在的。

耶鲁公开课 - 死亡课程节选

But the presence of the dog there is a conditioned stimulus and so you grew to be afraid of dogs.

而这时狗的存在就变成了条件刺激,所以你开始对狗心生恐惧。

耶鲁公开课 - 心理学导论课程节选