135556
The airfield was built as a temporary wartime field by Army Engineers , using Pierced Steel Planking ( PSP ) for runways and parking and dispersal areas , and support structures being quickly constructed out of wood or tents .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None