4509
As altitude increases from the base plate , yield strength decreases from 681 MPa to 579 MPa and ultimate tensile strength from 791 MPa to 686 MPa .
 As, yield strength, MPa, MPa, ultimate tensile strength, MPa, MPa
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:
 As, yield strength, MPa, MPa, ultimate tensile strength, MPa, MPa