20135
METHODS : Male Sprague - Dawley rats received five nicotine ( 0 . 0 , 0 . 2 or 0 . 4 mg / kg ) , TPM ( containing 0 . 2 or 0 . 4 mg / kg nicotine ) or methamphetamine ( 0 . 5 mg / kg ) injections every second day , followed by a 4 - day withdrawal before the first challenge ( Challenge 1 , C1 ) .
 Chemical: nicotine; Chemical: nicotine; Chemical: methamphetamine
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; Chemical: nicotine; Chemical: methamphetamine