低合金钢管板垂直固定平位焊时，最好采用（）。
A、左焊法、中性焰
B、左焊法、氧化焰
C、右焊法、中性焰
D、右焊法、碳化焰
参考答案：A
以下物理学家和物理学贡献的对应关系中不正确的是[ ]
A．汤姆生－发现了中子
B．盖尔曼－提出夸克设想
C．哥白尼－日心说
D．卢瑟福－原子核式模型
How disappointing it was that I _____ the wonderful football match. [ ]
A. may have missed
B. should have missed
C. could have missed
D. must have missed
