1087
The copper feedstock was prepared by distributing copper oxides through the copper matrix via mechanical milling , and that powder was then printed into a green geometry through BJAM .
 material: copper; material: copper oxides; material: copper; manufacturing process: mechanical milling; material: powder; concept or principle: geometry
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: copper, copper oxides, copper, mechanical milling, powder, geometry 
Answer:
 material: copper; material: copper oxides; material: copper; manufacturing process: mechanical milling; material: powder; concept or principle: geometry