从那天起，冷空气将进一步扩大影响范围。中国东北、内蒙古东部和许多其他西北地区的平均气温下降到零摄氏度以下。中国有句谚语，把霜降后的日子称为“三待”：待豺狼猎藏，待叶草枯黄，待蛰虫冬眠。

Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient ...