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 ...

美国白宫26日发表声明说，由于哥伦比亚政府已同意接收美国遣返的哥移民，美政府将暂停对哥加征关税等事宜。但白宫强调，此前由美国国务院发布的对哥签证制裁将继续生效至第一批被遣返移民抵达哥伦比亚为止。