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: These results suggest that hormonal replacement therapy can be safely prescribed if the following criteria are satisfied : 1 ) preliminary evaluation of patients from a clinical , metabolic , cytologic , and mammographic perspective ; 2 ) cyclic treatment schedule , with a progestative phase of 10 days ; and 3 ) periodic complete follow - up , with accurate thermographic evaluation of the breast target tissues .
### Output Text:
These results suggest that hormonal replacement therapy can be safely prescribed if the following criteria are satisfied : 1 ) preliminary evaluation of patients from a clinical , metabolic , cytologic , and mammographic perspective ; 2 ) cyclic treatment schedule , with a progestative phase of 10 days ; and 3 ) periodic complete follow - up , with accurate thermographic evaluation of the breast target tissues . 