11619
Thus , before getting down to work on the final version of each piece , he made numerous trials , using different proportions of iron oxide , trying different temperatures , sometimes buffing the piece to make it glossy and other times not , to get as close as possible to the correct overall effect .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: date, organization, person, geographical social political, national religious political, facility, cardinal, location, work of art, law, event, product, ordinal, percent, time, quantity, money, language 
Text: {0} 
 Entities:  
Answer:
 None