coal oven gas

例句：

1. 1. The factory produces a lot of coal smoke during the day.
   这家工厂在白天产生大量的煤烟。
2. 2. The coal gas is harmful to health.
   煤烟对人体有害。
3. 3. The coal gas is used in cooking and heating.
   煤烟用于烹饪和取暖。