对防止热裂纹有效的措施是()
A.烘干焊条
B.清除锈、水、油污
C.填满弧坑
D.焊后热处理
参考答案:C
——Thank you very much for everything , You’ve been so helpful.
—— ,Just let me know if there is anything else I can do for you.
A.With pleasure
B.My pleasure
C.Please don’t say so
D.Never mind
试述山豆根、射干、马勃的功效与主治的相同点和不同点。