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: Regarding HIT II , there were four ( 1 . 95 % ) patients with a background of HIT type II .
### Output Text:
Regarding HIT II , there were four ( 1 . 95 % ) patients with a background of HIT type II . 