Zài / tuǒ / yuán / guǐ / dào / zhōng / piān / xīn / lǜ / jué / dìng / guǐ / dào / de / biǎn / cháng / chéng / dù在椭圆轨道中,偏心率决定轨道的扁长程度。In an elliptical orbit, eccentricity determines how elongated the orbit is.