焊接工艺性优良的金属材料是()。
A、中碳钢
B、低碳钢
C、中碳合金钢
D、高碳钢
参考答案:B
You here half an hour earlier. It is a pity you missed the famous star. [ ]
A. must have come
B. might have come
C. Should have come
D. could have come
全面质量管理的基本理念。