2873
( voice - over ): But among the boats , guns , radar , sonar and communications , we found a secret weapon posted on the side of the tent that serves as the command center : letters from second - graders .
 graders: entity
Given event type and trigger, please tell me the arguments of all the listed option. Output format is "name1: role1; name2: role2". 
Event type: phone write 
  Option: entity, place 
Text: {0} 
Answer:
 graders: entity