We currently move around 1,000 to 2,000 kilograms of machinery to transport only one or just a few people, each weighing perhaps 75 kilograms (165 lbs.). And we do so using an internal combustion engine that utilizes only a small part of the energy released by burning the gasoline.
比如，我们可以考虑一下汽车能效问题。目前，我们正在使用1 000到2 000公斤的机器运送一个或数个人，每个人的重量大约为75公斤。汽车所使用的内燃机只能利用汽油燃烧所释放的能量的一小部分。大部分能量以废热的形式浪费掉了。