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In this research 3D printing is considered not as a question , but as an answer to the increasing scarcity of material resources in the construction industry .
 concept or principle: research; manufacturing process: 3D printing; material: as; material: as; material: material; application: construction
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: research, 3D printing, as, as, material, construction 
Answer:
 concept or principle: research; manufacturing process: 3D printing; material: as; material: as; material: material; application: construction