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By controlling laser scan properties interacting with the powder bed directly , porous structures can be generated by selectively sintering powder particles .
 enabling technology: laser scan; machine or equipment: powder bed; machanical property: porous; material: be; manufacturing process: sintering; material: powder particles
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: laser scan, powder bed, porous, be, sintering, powder particles 
Answer:
 enabling technology: laser scan; machine or equipment: powder bed; machanical property: porous; material: be; manufacturing process: sintering; material: powder particles