551
But in such close - quarters fighting , they would lose much of the technological advantage of their air supremacy , which would have to be curtailed because bombing in a city can cause large civilian casualties .
 they: attacker
Given event type and trigger, please tell me the arguments of all the listed option. Output format is "name1: role1; name2: role2". 
Event type: attack 
  Option: victim, attacker, place, target, instrument 
Text: {0} 
Answer:
 they: attacker