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 conclusion we found that thiazide diuretics cause hypokalemia and depletion of body potassium .
### Output Text:
In conclusion we found that <span class="chemical">thiazide</span> diuretics cause hypokalemia and depletion of body <span class="chemical">potassium</span> . 