6735
There is the significant reduction of the surface roughness and the bcc α-martensite phase on the SLM-MS .
 concept or principle: reduction; machanical property: surface roughness; concept or principle: bcc; concept or principle: phase
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: reduction, surface roughness, bcc, phase 
Answer:
 concept or principle: reduction; machanical property: surface roughness; concept or principle: bcc; concept or principle: phase