1357
As the use of support structure is generally not appropriate when printing at these scales , understanding the limits of overhanging feature angles is necessary to establish the economic case for using large 3D printing .
 material: As; engineering feature: support structure; concept or principle: limits; engineering feature: overhanging feature; manufacturing process: 3D printing
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: As, support structure, limits, overhanging feature, 3D printing 
Answer:
 material: As; engineering feature: support structure; concept or principle: limits; engineering feature: overhanging feature; manufacturing process: 3D printing