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: The protective action of subcutaneously ( SC ) administered antidotes or their combinations in DFP ( 2 . 0 mg / kg BW ) intoxication was studied in 9 - 10 - weeks - old Han - Wistar male rats .
### Output Text:
The protective action of subcutaneously ( SC ) administered antidotes or their combinations in <span class="chemical">DFP</span> ( 2 . 0 mg / kg BW ) intoxication was studied in 9 - 10 - weeks - old Han - Wistar male rats . 