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: Further , steroid myopathy recovers naturally and the neurological improvement shown in the NASCIS may be just a recording of this natural motor recovery from the steroid myopathy , instead of any protection that methylprednisolone offers to the spinal cord injury .
### Output Text:
Further , <span class="chemical">steroid</span> myopathy recovers naturally and the neurological improvement shown in the NASCIS may be just a recording of this natural motor recovery from the <span class="chemical">steroid</span> myopathy , instead of any protection that <span class="chemical">methylprednisolone</span> offers to the spinal cord injury . 