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: We used rat models of intrahepatic cholestasis by ethinyl estradiol ( EE ) treatment and extrahepatic cholestasis by bile duct ligation ( BDL ) to precisely determine the site of TJ damage .
### Output Text:
We used rat models of intrahepatic cholestasis by <span class="chemical">ethinyl estradiol</span> ( <span class="chemical">EE</span> ) treatment and extrahepatic cholestasis by bile duct ligation ( BDL ) to precisely determine the site of TJ damage . 