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: Therefore , we studied the predictive effect of renal ACE activity for the severity of renal damage induced by a single injection of adriamycin in rats .
### Output Text:
Therefore , we studied the predictive effect of renal ACE activity for the severity of renal damage induced by a single injection of <span class="chemical">adriamycin</span> in rats . 