zài / wēi fēn jǐ hé / zhōng / qū lǜ / hé / náo lǜ / shì / qū xiàn / de / jī běn / bù biàn liàng在微分几何中,曲率和挠率是曲线的基本不变量。In differential geometry, curvature and torsion are basic invariants of curves.