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: Two separate equimolar doses ( 0 . 2 and 0 . 4 mumol ) of either cocaine or BE were injected ventricularly in unanesthetized juvenile rats .
### Output Text:
Two separate equimolar doses ( 0 . 2 and 0 . 4 mumol ) of either <span class="chemical">cocaine</span> or <span class="chemical">BE</span> were injected ventricularly in unanesthetized juvenile rats . 