In this task, you are given a paragraph, event and an entity. The event is part of the given paragraph and it changes the state of the entity. Your task is to classify the state of the entity into three classes: 1) not exist, 2) unknown location and 3) known location. "not exist" means the entity doesn't exist in that state anymore. "unknown location" means the entity exists in that state but location is unknown. "known location" means the entity exists and location is known. 
Q:  "process paragraph : : Water is introduced to carbon dioxide. The water becomes acidic. The water seeps down to a mineral based material. The acidity of the water carves and shapes the rock. And may form geological phenomenon. ", "event : The water becomes acidic.", "entity : water" 
A: 
 unknown location 