Gamma-amino butyric acid, or GABA, for example, is a chemical thatshuts down nerve cells.

如γ-氨基丁酸或伽马氨基丁酸，都是可以使神经细胞关闭化学物质。

The small orange-colored " fruit" is, in fact, ginkgo seeds, which have several layers. The fresh outer layer has butyric acid, the main source of the smell.

银杏果有好几，果含有丁酸——也是它臭味主要来源。

And any given odorant, like this pizza, is made up of hundreds of different chemicals that you can smell, like the thymol of the oregano, the butyric acid of the cheese, and the acetylpyrazine of the crust.

任何特定气味，比如这个披萨，是由你能闻到数百种不同化学物质组成，比如牛至百里香酚，奶酪丁酸，和乙酰吡嗪。