1943
Hence , TO methods and tools to help designers to allocate different material to different regions with optimal quantities for an expected multi-functional structure become critical .
 machine or equipment: tools; material: material; concept or principle: multi-functional structure
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: tools, material, multi-functional structure 
Answer:
 machine or equipment: tools; material: material; concept or principle: multi-functional structure