Subject + 存在 + 于 + Location
The verb 存在 (cúnzài) means "to exist" or "to be present." It is used to state that something is found or occurs in a particular place or situation. For example, 存在于小行星上 means "exists on an asteroid."
这个问题已经存在很久了。
zhège wèntí yǐjīng cúnzài hěn jiǔ le.
This problem has existed for a very long time.
地球上存在着各种各样的生物。
Dìqiú shàng cúnzài zhe gè zhǒng gè yàng de shēngwù.
There are all kinds of living organisms on Earth.
他们之间存在很大的分歧。
Tāmen zhījiān cúnzài hěn dà de fēnqí.
There is a great deal of disagreement between them.