3630
In case of refractory metals , the difficulty is amplified because of their high melting point and brittle behaviour .
 material: refractory metals; machanical property: melting point; machanical property: brittle
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: refractory metals, melting point, brittle 
Answer:
 material: refractory metals; machanical property: melting point; machanical property: brittle