2076
with the pollution caused by the buring of coal , the light-colored tree trunks became darker due to soot .
 cause effect: pollution, buring
Given options, please tell me the relationships of all the listed entity pairs.Output format is "relation1: word1, word2; relation2: word3, word4". 
Option: component whole, NA, instrument agency, member collection, cause effect, entity destination, content container, message topic, product producer, entity origin 
Text: {0} 
 Entity Pairs:  pollution, buring 
Answer:
 cause effect: pollution, buring