Over three-quarters of them by hand.

其中超过四分之三仅靠人力
Agriculture is like a tradition handed down...

农业像是一种传统在汗水和辛苦劳作中
From generation to generation in sweat, graft and toil,

从一代传到下一代
Because for humanity it is a prerequisite of survival.

因为这是人类生存的前提
But after relying on muscle power for so long,

但在长期依赖肉体能量之后
Humankind found a way to tap into the energy buried deep in the earth.

人类发现了取得深埋于地下的能量的方法
These flames are also from plants.

这些火焰也是来自植物
A pocket of sunlight.

是累积的太阳光
Pure energy the energy of the sun

纯粹的能量太阳能
Captured over millions of years by millions of plants...

是一亿多年前
More than a hundred million years ago.

数以百万的植物历经百万年捕获的
It's coal. it's gas.

有煤炭天然气