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Moreover , the fracture toughness of the prepared samples gradually increased as the scanning speed increased , while the flexural strength showed a parabolic law behavior .
 fracture, samples, as, scanning speed, flexural strength
Please list all entity words in the text that fit the category. Output format is "word1, 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:
 fracture, samples, as, scanning speed, flexural strength