1922
The author of also understands that it would be hard to avoid the use of support structure , and proposed to optimize the 3D structure with necessary support structure in parallel so as to obtain a better compromise .
 material: be; engineering feature: support structure; concept or principle: 3D structure; engineering feature: support structure; material: as
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:
 material: be; engineering feature: support structure; concept or principle: 3D structure; engineering feature: support structure; material: as