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Separate groups of mice underwent 3 consecutive days of the same exposure sequence for 3h each consisting of the following : ( 1 ) 6h of filtered air ( FAFA ) , ( 2 ) O ( 3 ) then FA ( O ( 3 ) FA ) , ( 3 ) FA then carbon black ( FACB ) , or ( 4 ) O ( 3 ) then CB .
 Chemical: O ( 3 ); Chemical: O ( 3 ); Chemical: carbon black; Chemical: O ( 3 )
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: O ( 3 ); Chemical: O ( 3 ); Chemical: carbon black; Chemical: O ( 3 )