1)major semi axis,长半轴2)semi-major axis,长半轴3)major semi-axis,长半轴4)semimajor axis of ellipsoid,椭球长半轴，地球长半轴5)Semi-major axis modification,长半轴修正6)semi major axis,长半径7)long D slide valve,长半园滑阀8)long-radius grating,长半径光栅9)drawing method of measuring point using half_value of line segment,边长半值量点法10)long half-life group,长半衰期(元素)组
用法例句
A practical perspective drawing method, a drawing method of measuring point using half_value of line segment, is put forward.
