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: RESULTS : Trazodone at 2 . 5 - 20 mg / kg i . p . did not induce catalepsy , and did not antagonize apomorphine ( 1 . 5 and 3 mg / kg ) stereotypy and apomorphine ( 0 . 05 mg / kg ) - induced catalepsy .
### Output Text:
RESULTS : <span class="chemical">Trazodone</span> at 2 . 5 - 20 mg / kg i . p . did not induce catalepsy , and did not antagonize <span class="chemical">apomorphine</span> ( 1 . 5 and 3 mg / kg ) stereotypy and <span class="chemical">apomorphine</span> ( 0 . 05 mg / kg ) - induced catalepsy . 