In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: In these animals , only minor increases of serum transaminase activities were measured in the presence of AAP , and unlike the exacerbation caused by ethanol in mice on a standard diet , the liver damage was inhibited by 50 % by ethanol .
### Output Text:
In these animals , only minor increases of serum transaminase activities were measured in the presence of <span class="chemical">AAP</span> , and unlike the exacerbation caused by <span class="chemical">ethanol</span> in mice on a standard diet , the liver damage was inhibited by 50 % by <span class="chemical">ethanol</span> . 