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Moreover , there was no difference in the % 5 - methyl - 2 ' - deoxycytidine content of DNA between the cocaine and the heroin treated animals .
 Chemical: 5 - methyl - 2 ' - deoxycytidine; Chemical: cocaine; Chemical: heroin
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: 5 - methyl - 2 ' - deoxycytidine; Chemical: cocaine; Chemical: heroin