13914
All three arsenicals disturbed cell cycle progression at cytotoxic concentrations , but failed to increase the level of reactive oxygen and nitrogen species ( RONS ) in healthy A549 cells .
 Chemical: oxygen; Chemical: nitrogen
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: oxygen, nitrogen 
Answer:
 Chemical: oxygen; Chemical: nitrogen