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The 3D printer developed by the Chinese group is much larger than a conventional system and uses the same DDM technology .
 machine or equipment: 3D printer; concept or principle: conventional system; enabling technology: DDM technology
Please list all entity words in the text that fit the category.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} 
Answer:
 machine or equipment: 3D printer; concept or principle: conventional system; enabling technology: DDM technology