美国俄亥俄州克利夫兰高地（Cleveland Heights）上周四（27日）一辆校车无故起火，幸好司机冷静应对，迅速地疏散学生。校巴后来完全陷入火海，事故没有造成人员伤亡。

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