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: BE - Injected rats that did not have seizures had significantly more locomotor activity than cocaine - injected animals without seizures .
### Output Text:
<span class="chemical">BE</span> - Injected rats that did not have seizures had significantly more locomotor activity than <span class="chemical">cocaine</span> - injected animals without seizures . 