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: During the first test 0 . 9 % NaCl was given i . v . ; during the second test 200 micrograms of hCRH ( n = 12 ) or 400 micrograms of TRH ( n = 6 ) was administered i . v . Nine subjects received 0 . 9 % NaCl i . v . during both rebreathing manoeuvres .
### Output Text:
During the first test 0 . 9 % <span class="chemical">NaCl</span> was given i . v . ; during the second test 200 micrograms of hCRH ( n = 12 ) or 400 micrograms of TRH ( n = 6 ) was administered i . v . Nine subjects received 0 . 9 % <span class="chemical">NaCl</span> i . v . during both rebreathing manoeuvres . 