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: Climbing behavior induced by apomorphine was reduced in animals treated with THP .
### Output Text:
Climbing behavior induced by <span class="chemical">apomorphine</span> was reduced in animals treated with <span class="chemical">THP</span> . 