Detailed Instructions: 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 : : Blood is sent to the liver. The liver uses chemicals and proteins to treat the blood. The blood is cleaned. Energy is produced. The blood leaves the liver cleaned. ", "event : The liver uses chemicals and proteins to treat the blood.", "entity : blood" 
A:
 known location 