the upper three feet of怎么翻译? Material for rings, lugs, saddles, wear/corrosion plates, legs supporting vessels, and the upper three feet of support skirts welded directly to the vessel or to reinforcing rings welded to the vessel shall be the same material as the shell when the design temperature is greater than 650ºF (340ºC). the upper three feet of support skirts welded directly to the vessel or to reinforcing rings welded to the vessel这个要怎么翻译,or后面跟了个to,要怎么理解? 查看更多7个回答 . 5人已关注