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: Cocaine - induced hyperactivity is more influenced by adenosine receptor agonists than amphetamine - induced hyperactivity .
### Output Text:
<span class="chemical">Cocaine</span> - induced hyperactivity is more influenced by <span class="chemical">adenosine</span> receptor agonists than <span class="chemical">amphetamine</span> - induced hyperactivity . 