Brazil discovered a 13,000 – year – old tunnel perhaps not built by humans

Scientists discovered thousands of mysterious （神秘的） tunnels in the mountains in southern and southeastern Brazil. Archaeologists （考古學家） claimed these tunnels are at least 13,000 years old and they were probably not built by humans.   The tunnels are distributed （分佈） throughout the rainforest and they vary in size. Some are only a dozen metres long, while others are hundreds of metres long. The longest one ...Read More