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The most well-known of these would be AM machines used in production of teeth aligners and hearing aids .
 material: be; machine or equipment: AM machines; manufacturing process: production; application: hearing aids
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: be, AM machines, production, hearing aids 
Answer:
 material: be; machine or equipment: AM machines; manufacturing process: production; application: hearing aids