Mysterious Fort Detrick of the U.S. Army, Unit 731 of the imperial Japanese Army, 250,000 yen... After WWII, the U.S. helped cover up the crimes of Unit 731, a covert Japanese biological and chemical warfare research and development unit and bought its biological warfare data for 250,000 Yen, "a mere pittance by comparison with the actual cost of the studies." What more secrets is Fort Detrick hiding from the world? (Source: Xinhua)