化石能源-煤、石油、天然气一次能源

展示内容：

一次能源包括煤、石油、天然气等，是一种碳氢化合物或其衍生物。它由古代生物的化石沉积而来，是一次性使用的能源。化石燃料不完全燃烧后，都会散发出有毒的气体，却是人类必不可少的燃料。

操作方法：

滚动台面上的滚筒，观察显示器内容。

Primary Energy Source

Exhibit Explanation:

Primary energy source is a kind of hydrocarbon compound or its ramification, which includes coal, petroleum and natural gas, etc. It is the deposition of the ancient biological fossil and nonrenewable source. The fossil fuels may give out poisonous gases when they are not fully burnt. However, they are still the essential fuels for humankind.

Operating Instruction:

Start the roller on the stand and watch the display.