"天地剧变，苦难无边"有生之年狭路相逢

　　National Geographic assesses the contenders for the worst natural disasters of all time those events that had severe impact on human populations. As well as examining the deadliest, we will also explore the most powerful, the most wide reaching and epoch changing events. We explain how they occurred, why they created such mayhem and explain what makes them qualify as one of our... (展开全部)