“煤烟”造句

煤烟是燃料不完全燃烧的产物.
Soot is the product of the imperfect combustion of fuel.

煤烟通常是燃料不完全燃烧的产物.
Soot is usually the product of the imperfect combustion of fuel.

烟囱里面很快就覆盖了一层煤烟.
The inside of a chimney soon gets covered in soot.