13115
Factors including gunpowder dosages , smog - exposure time , the cell density , modes of exposure , volumes of smog , test durations , volumes of the cell culture medium and combustion velocity were measured .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None