77993
History Formation in World War I No. 136 squadron was officially formed on 1 April 1918 at Lake Down , as a service unit - not a training unit - , working up for the Airco DH .9 , using a variety of aircraft .
 No. 136
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 No. 136