coke number

例句：

1. 1. The coal tar content in the oil is 20%.
   该石油中的煤焦油含量为20%。
2. 2. This product has a high tar content, which can cause health problems.
   该产品含高焦油量，可能引起健康问题。
3. 3. The company's policy on environmental protection is to reduce the coke number and increase energy efficiency.
   该公司的环保政策是减少焦油含量并提高能源效率。