一、烟草烟草是一种布科植物。利用烟草作为杀虫剂在我国已有悠久历史，但其中的有效成分烟流的发现．则是19世纪初的事。烟田对昆虫有日每、伯乐及意达三种作用，使昆虫死亡的原因在于成四神经，烟减的蒸气可自虫体任何部分巴人体内发挥毒杀作用。①烟草粉把烟叶晒干后回成粉? First, tobacco Tobacco is a kind of cloth plants. The use of tobacco as a pesticide in our country has a long history, but the discovery of the active ingredient smoke. It is the early 19th century thing. Tobacco fields have insects every day, Bole and Italy up to three kinds of roles, so that the cause of death of insects into a four nerve, the smoke can reduce the steam from any part of the body to play a poisonous effect. ① tobacco powder to dry the leaves back into the powder?