natural year glossary / natural year Hist. The period of 365 days and about 6 hours, or the time it takes the earth to orbit the sun. natural year Read More »
natural year glossary / natural year, 回归年, 天文年 natural year 回归年;天文年 指地球环绕太阳一周的时间,即3651/4天。 natural year Read More »