3210
In a single semester of the course , teams created prototype machines for 3D printing of molten glass , 3D printing of soft-serve ice cream , robotic deposition of biodegradable material , direct-write deposition of continuous carbon fiber composites , large-area parallel extrusion of polymers , and in situ optical scanning during 3D printing .
 prototype, machines, 3D printing, molten glass, 3D printing, deposition, biodegradable material, deposition, continuous carbon fiber, composites, extrusion, polymers, in situ, scanning, 3D printing
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:
 prototype, machines, 3D printing, molten glass, 3D printing, deposition, biodegradable material, deposition, continuous carbon fiber, composites, extrusion, polymers, in situ, scanning, 3D printing