两只虎鲸跃出水面。图片由 Robert Pittman 拍摄，640px-Killerwhales_jumping 通过 Wikimedia Commons 提供。 Orcas, or killer whales, and great white sharks are apex predators that rule the oceans. However, the answer might ...

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

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