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: A control group was included for comparison with the lower dose range of glycopyrrolate and atropine .
### Output Text:
A control group was included for comparison with the lower dose range of <span class="chemical">glycopyrrolate</span> and <span class="chemical">atropine</span> . 