求翻译：焊接优选双面焊。手工电弧焊接前，应将焊口两侧的铁锈、油脂、污垢等清除干净，使焊缝成金属光泽，在焊接过程中，应采取有效措施，不使受风、雪、冰、霜和雨水的侵蚀，当工作环境的风力大于5级、雪天或相对湿度大于90%时，应采取保护措施施焊；焊接时，应使焊缝可自由伸缩，并应使焊口缓慢降温；冬期焊接时，应根据环境温度进行预热处理并应符合下表的规定。是什么意思？

Double-sided welding welding preferred. Manual arc welding done, the weld on both sides of rust, grease, dirt, etc. cleaned, the weld into a metallic luster, in the welding process, should take effective measures, not to the wind, snow, ice, frost and rain erosion, when the work environment is great

welding preferred double-sided welding. Manual arc welding, welding mouth should be either side of the rust, grease, dirt, and other out clean welds, so that in a metallic Luster, welding, effective measures should be taken so as not to have the wind, snow, ice, frost and rain erosion, when the work

Optimization of welded duplex weld. Hand electric arc welding Qian, should will welded joints on both sides of of rust, and oil, and dirt, clear clean, makes weld into metal gloss, in welding process in the, should take effective measures, does not makes by wind, and snow, and ice, and cream and rai