coal tar

例句：

1. 1. The coal tar was used to make inks and paints.
   煤焦油被用来制作墨水和油漆。
2. 2. Coal tar is a byproduct of the coal industry.
   煤焦油是煤炭工业的副产品。
3. 3. The coal tar residue left on the surface of the furnace can be cleaned off with soap and water.
   炉子表面的煤焦油残留物可以用肥皂水清洗掉。