So they give off carbon dioxide.

所以它们会释放二氧化碳。

146.All of us should be grateful to what nature offers us, obey the natural laws, maintain the balance of nature and ban burning any harmful l substance and giving off carbon dioxide through the chimneys.

我们应当用感激的心回报答自然的恩赐，遵守大自然的规律，维护生态平衡，禁止燃烧任何有害物质，严禁烟囱里释放二氧化碳。