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: In Dahl salt - sensitive rats ( DS ) , high - salt ( HS ) diet increases BP more in males than females .
### Output Text:
In Dahl <span class="chemical">salt</span> - sensitive rats ( DS ) , high - <span class="chemical">salt</span> ( HS ) diet increases BP more in males than females . 