1780
Careful attention must be given to beam control so that they do n't affect each other , including the vapour trails from the molten metal regions .
 material: be; process parameter: beam control; material: molten metal
Please list all entity words in the text that fit the category.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} 
Answer:
 material: be; process parameter: beam control; material: molten metal