Your great-great grandparents got by on muscle power, and yet we all think there's this huge power that's essential for our lifestyle. And with all the wonderful technology we have we can do things that are much more efficient: conserve, recycle, etc.
你们的曾曾祖父靠肌肉力量生存 而我们都认为我们的生活方式主要是靠着某种巨大的力量支持。 依靠我们所有的这些神奇的技术 我们可以做更有效的事情：生态保护，循环利用等。