Q: 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. 
 "process paragraph : : Several types of gases form in the atmosphere. May come from different sources. The gases remain trapped in the atmosphere. Through the suns light the gases hold in heat and energy. Trap them in our atmosphere. The earth may become warmer this way. ", "event : May come from different sources.", "entity : several types of gases" 
A:
 known location 