自然灾害无情，亟需防范。妞千网最新免费视频

　　May 22, 2011, the costliest tornado in American history struck Joplin, Missouri, carving a mile-wide swath of destruction and death. Scientists descended on the city to find out what made this tornado so destructive. This film visits Joplin at the five-year mark, as its people continue to pick up the pieces and struggle to make sense of one of the worst natural disasters ever t... (展开全部)