Cigarettes (pinyin: yān) are first-class Chinese characters. The radical "_" is simplified to "cause". Save strokes and simplify them according to ancient calligraphy. "Shuo Wen Jie Zi": "Smoke, anger also. Stay away from flames and sounds. Smoke, or from the cause. " . The blockage in soil habitat is _. The two paradigms of fire and _ _ are superimposed, and it is the paradigm of smoke that blocks fire and produces internal heat due to incomplete combustion.