17957
Results were compared with those from earthworms exposed to cadmium nitrate and selenious acid , as positive controls , and those exposed in untreated soil ( negative control ) .
 Chemical: cadmium nitrate; Chemical: selenious acid
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: cadmium nitrate, selenious acid 
Answer:
 Chemical: cadmium nitrate; Chemical: selenious acid