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: This observation shows that clotiazepam can induce acute hepatitis and suggests that there is no cross hepatotoxicity between clotiazepam and several benzodiazepines .
### Output Text:
This observation shows that <span class="chemical">clotiazepam</span> can induce acute hepatitis and suggests that there is no cross hepatotoxicity between <span class="chemical">clotiazepam</span> and several <span class="chemical">benzodiazepines</span> . 