基本解釋[數(shù)學(xué)]直紋二次曲面詞組短語(yǔ)短語(yǔ)Research of the Ruled Quadric 二次曲面討論Quadric ruled surface 二次直紋面ruled quadric更多詞組專業(yè)釋義數(shù)學(xué)直紋二次曲面