29976
METHODS : Double - blind , randomised , placebo - controlled study in which 132 dependent smokers abstained for 6 h with the assistance of either nicotine ( 2 mg , n = 42 or 4 mg , n = 24 ) or placebo ( n = 66 ) gum while travelling on a non - smoking train .
 Chemical: nicotine
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: nicotine