在进入21世纪的今天,开发新能源用以替代传统能源其难度之大是前所未有的。人类有数千年依靠木材生火的历史,后人类又学会了使用煤作为能源;而工业化社会又引来了石油。有了石油后,陆路和空中运输才得以迅猛发展。此时,人们几乎把过去烧火用的木材或者煤炭给淡忘了,也不经常去 In the 21st century, it is more difficult than ever to develop new energy sources to replace traditional energy sources. Humans have relied on the history of wood burning for thousands of years, and later humans learned to use coal as their source of energy; in turn, industrialized society drew oil. With the oil, land and air transport have been able to develop rapidly. At this moment, people almost forgotten the wood or coal used for burning fire, and often did not go