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: Streptomycin was administered to the inner ear by osmotic pump for 24 h , and edaravone ( n = 8 ) or saline ( n = 6 ) was intraperitoneally injected once a day for 7 days .
### Output Text:
<span class="chemical">Streptomycin</span> was administered to the inner ear by osmotic pump for 24 h , and <span class="chemical">edaravone</span> ( n = 8 ) or saline ( n = 6 ) was intraperitoneally injected once a day for 7 days . 