2-4-3

second,when electrical energy in the form of moving electrons flows throughfilament wires in an incandescent light bulb, about 5% of into useful light and95% flows into the environment as low-quality heat. in other words, the incandescentlight bulb is really an energy-wasting heat bulb.

第二，當電能的形式，移動電子流經纖維絲的白熾燈泡，約5 ％的轉化為有用的光線和95 ％流入環境低質量的熱量。換言之，白熾燈燈泡實際上是浪費能源熱燈泡。

Third,in living systems,solar energy is converted into chemical energy(food molecules)and then into mechanical energy(for moving,thinking,and living).During each conversion,high-quality energy is degraded and flows into the environment as low-quality heat.Trace the flows and energy conversions in Figure 2-7 to see how this happens.

第三，在生物系統，太陽能轉化為化學能（食品分子） ，然後為機械能（移動，思想和生活） 。 在每次轉換，高品質的能源是退化和流入環境低質量的熱量。 微量的流動和能量轉換圖2-7看到這種情況發生。