A replicator must exist long enough to be able to get copied, and transfer its information.

复制因子必须存在足够久，才能被复制并传递信息。

youdao

Some people believe that there may not exist a stress gap between men and women.

有些人认为，男性和女性之间可能不存在压力差距。

youdao

Research opportunities exist in a wide range of areas.

研究机会存在于广泛的领域中。

《柯林斯英汉双解大词典》

This is one of the few photographs known to exist of a very dangerous man named James Miller.

VOA: special.2010.03.17

If I can tell a story in which A exists and B doesn't exist, it's got to follow that A and B are not the same thing.

如果我跟你说A存在但B不存在,就可以得出结论A和B不是一个东西

耶鲁公开课 - 死亡课程节选

you can't imagine a world in which A exists but A doesn't exist.

你无法想象一个A既存在又不存在的世界

耶鲁公开课 - 死亡课程节选

Under current law, a connection must exist to a specific individual.

CNN: Ashcroft says lawmakers moving too slowly

For example, one reason new photo app Snapchat has become enormously popular lately, may be because it lets users decide how long a photo will exist (usually a few seconds) before it self-destructs.

FORBES: Instagram Boycott Now Includes National Geographic And Anonymous

Is OnLive a service that could exist in a higher-bandwidth future but not in our mediocre bandwidth present?

FORBES: OnLive Denies Shutting Down But Multiple Sources Confirm Layoffs