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 4 1 / 2 - year - old girl who was treated with high - dose carboplatin for metastatic parameningeal embryonal rhabdomyosarcoma .
### Output Text:
We report a 4 1 / 2 - year - old girl who was treated with high - dose <span class="chemical">carboplatin</span> for metastatic parameningeal embryonal rhabdomyosarcoma . 