普通低碳钢属于黑色金属,最常采用哪种焊接()?A、电焊 B、氩弧焊 C、气焊 D、钎 发布时间:2019-06-28 16:02 │ 来源:www.tikuol.com 题型:单项选择题 问题: 普通低碳钢属于黑色金属,最常采用哪种焊接()?A、电焊B、氩弧焊C、气焊D、钎焊
题型:单项选择题 She brought with her three friends, none of ______ I had ever met before. A.themB.whoC.whomD.these 查看答案