n.（船的）龙骨；vt.& vi.翻身，倾覆；adj.无龙骨的； 变形： 复数：keels过去式：keeled过去分词：keeled现在分词：keeling第三人称单数：keels 英英释义： keel[ ki:l ]n.the median ridge on the breastbone of birds that flyone of the main longitudinal beams (or plates) of the hull of a vessel; can extend verticall