383380
He proposed that there were three insurmountable difficulties in the Copenhagen Interpretation , including the negation of causality and realism , along with the need for " involvement of infinite and imaginary velocities or masses " .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities:  
Answer:
 None