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: Lipopolysaccharide pretreatment did not affect the basal body temperature or methamphetamine - elicited hyperthermia three days later .
### Output Text:
<span class="chemical">Lipopolysaccharide</span> pretreatment did not affect the basal body temperature or <span class="chemical">methamphetamine</span> - elicited hyperthermia three days later . 