The dream of sustainable air travel is now one step closer to reality, after a team of researchers in Germany flew a plane that emits nothing but water vapor into the atmosphere.
원문출처 : http://www.cnn.com/2016/10/19/world/hy4-fuel-cell-plane/index.html
원문출처 : http://www.cnn.com/2016/10/19/world/hy4-fuel-cell-plane/index.html