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 report a patient with primary biliary cirrhosis , who developed polymyositis while receiving D - penicillamine therapy .
### Output Text:
We report a patient with primary biliary cirrhosis , who developed polymyositis while receiving <span class="chemical">D - penicillamine</span> therapy . 