22980
24 male rats , 5weeks old , were divided into three groups with different diets ( C : control , 2mg OPE : chow diet with 2mg OPE supplementation , 10mg OPE : chow diet with 10mg OPE supplementation ) for 6weeks .
 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