气味是挥发的微量化学物质在动物大脑引起的反应。人的嗅觉固然不如其他动物灵敏,然而,却能巧妙地利用气味,让它在生产、生活中发挥作用。有一种叫“乙硫醇”的物质,只要空气中存在五千亿分之一,人们就足以闻出它那强烈的臭味。因此,如将极微量的乙硫醇混 Odor is the reaction of volatile trace chemicals in the animal’s brain. Although the human sense of smell is not as sensitive as other animals, however, it can skillfully use the smell, let it play a role in the production and life. There is a substance called “ethanethiol”, and as long as there are one hundredths of a billionth of an inch in the air, people are enough to smell its strong odor. Therefore, such as a trace amount of ethanethiol mixed