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Titanium dioxide ( TiO2 ) are among most frequently used nanoparticles ( NPs ) .
 Chemical: Titanium dioxide; Chemical: TiO2
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: Titanium dioxide, TiO2 
Answer:
 Chemical: Titanium dioxide; Chemical: TiO2