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: CASE SUMMARY : A 70 - year - old healthy woman from Iraq developed acute cholestatic hepatitis 3 weeks following repair of the right rotator cuff under general anesthesia .
### Output Text:
CASE SUMMARY : A 70 - year - old healthy woman from Iraq developed acute cholestatic hepatitis 3 weeks following repair of the right rotator cuff under general anesthesia . 