----- 初等欧几里德几何
1. Points and lines 2. The Euclidean plane 3. Circles 4. General conics 5. Centres of general conics 6. Degenerate conics 7. Axes and asymptotes 8. Focus and directrix 9. Tangents and normals 10. The parabola 11. The ellipse 12. The hyperbola 13. Pole and polar 14. Congruences 15. Classifying conics 16. Distinguishing conics 17. Uniqueness and invariance.
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