9425
In the arc model , the molten pool is simplified to be solid state on the basis of experimentally observed results .
 arc, molten pool, be
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:
 arc, molten pool, be