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: In addition , we demonstrate that mice genetically engineered to have unilateral brain DA deficits develop METH - induced dopaminergic deficits that are of comparable magnitude on both sides of the brain .
### Output Text:
In addition , we demonstrate that mice genetically engineered to have unilateral brain <span class="chemical">DA</span> deficits develop <span class="chemical">METH</span> - induced dopaminergic deficits that are of comparable magnitude on both sides of the brain . 