2039
Melt pool surface sampling by LIBS probe was demonstrated to be the only choice for quantitative elemental analysis .
 Melt pool, sampling, probe, be, quantitative, elemental analysis
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:
 Melt pool, sampling, probe, be, quantitative, elemental analysis