焊缝是熔池金属冷却结晶所形成的铸态组织,其性能不低于基体金属。( )
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酸性焊条的工艺性比碱性焊条的工艺性好。( )
A. 对
B. 错
碱性焊条的电弧稳定性比酸性焊条好。( )
A. 对
B. 错
Exercise 1Column A: build, waste, oral, potential, raiseColumn B: presentation, confidence, money, problem, timeStudents communicate their information via an ____and a written report.
We help our client ____and competence to success in the English world.