单项选择题
A.40~50℃B.25~35℃C.15~25℃D.60~70℃
A.1/4B.1/2C.1/3D.1/5
A.先胀后焊B.焊接C.先焊后胀D.胀接
A.5~10mmB.10~20mmC.20~50mmD.50~70mm
微信扫一扫,加关注免费搜题