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: The administration of several benzodiazepines , chemically related to clotiazepam , did not interfere with recovery and did not induce any relapse of hepatitis .
### Output Text:
The administration of several <span class="chemical">benzodiazepines</span> , chemically related to <span class="chemical">clotiazepam</span> , did not interfere with recovery and did not induce any relapse of hepatitis . 