7008
Oxidation , predominantly in the form of spots or films of Al2O3 and TiO2 was observed on the surface of some of the spatter particles .
 manufacturing process: Oxidation; material: Al2O3; material: TiO2; concept or principle: surface; process characterization: spatter; concept or principle: particles
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
 Entities: Oxidation, Al2O3, TiO2, surface, spatter, particles 
Answer:
 manufacturing process: Oxidation; material: Al2O3; material: TiO2; concept or principle: surface; process characterization: spatter; concept or principle: particles