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: METHOD : We analyzed data from the Studies of Left Ventricular Dysfunction ( SOLVD ) , a randomized , double - blind , placebo - controlled trial of enalapril for the treatment of CHF .
### Output Text:
METHOD : We analyzed data from the Studies of Left Ventricular Dysfunction ( SOLVD ) , a randomized , double - blind , placebo - controlled trial of <span class="chemical">enalapril</span> for the treatment of CHF . 