7月一个醉人的傍晚，这一家人下了火车。在金色的夕阳下，田野和树木看上去美极了，鸟儿欢快地唱着歌，天空一片蔚蓝。可就在他们到达坎特维尔古堡的时候，天空中出现了乌云，十来只巨大的黑鸟盘旋在他们的头顶上，接着豆大的雨点便开始落下来。

Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient world slept only 6.5 hours a night.

Scientists researching Alpine glaciers store ice in Antarctica. By analysing air bubbles in the ice they may be able to predict the future ...