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Whereas several studies have demonstrated the potential of RMC as a suitable and environment-friendly construction material , this study reports that RMC can be shaped into complex structures via three-dimensional ( 3D ) printing technology .
 RMC, as, construction, RMC, be, complex structures, three-dimensional, 3D, printing technology
Please list all entity words in the text that fit the category. Output format is "word1, 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} 
Answer:
 RMC, as, construction, RMC, be, complex structures, three-dimensional, 3D, printing technology