合成丸丸子

　　They were once considered the future of warfare: flying aircraft carriers the size of the Titanic, able to hold five fighter planes. In the 1920s and '30s, the U.S. military had high hopes for these zeppelins, but instead of carrying aviation forward, the airship era would be brief and tragic. Witness the rise and fall of this failed weapon of war and follow a team of scientist... (展开全部)