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: Of these 352 patients , eight patients suffered bilateral abductor paralysis , and two suffered this complication twice .
### Output Text:
Of these 352 patients , eight patients suffered bilateral abductor paralysis , and two suffered this complication twice . 