tobacco smoke alkaloid

例句：

1. 1.Tobacco smoke is a major contributor to air pollution.
   烟草烟雾是空气污染的主要来源。
2. 2. The alkaloidin tobacco smoke has been shown to havehealth benefits.
   烟草烟雾中的生物碱已被证明具有健康益处。
3. 3. Smoking isknown to increase the risk of lung cancer, which is caused by the alkaloid in tobacco smoke.
   吸烟已知会增加患肺癌的风险，而肺癌是由烟草烟雾中的生物碱引起的。