金属材料焊接性好坏主要决定于材料的化学成份。
参考答案：对
--Did you do _____ interesting yesterday? --Yes, ______.
A．anything, I did
B．anything, I was
C．something, I did
D．something, I was
提高直流炉水动力稳定性的方法有哪些？
