A for acetyl, and spir for meadowsweet, whose botanical name is Spiraea ulmaria.

A 代表乙酰基，spir 代表绣线菊，其植物是 Spiraea ulmaria。

Epigenetics—currently one of molecular biology's hottest topics —is a process by which genes are activated or deactivated by the presence or absence of chemical structures called methyl and acetyl groups.

表现遗传——目前分子生物最热的题之一——是这样一个过程，基因的激活或是失效取决于甲基和乙酰基的化结构的存在或是消失。

It replaced one of salicylic acid's hydroxyl group — that's an oxygen and hydrogen bonded to a carbon — with an acetyl group, which is two carbons, one double-bonded to an oxygen and the other bonded to three hydrogens.

它用乙酰基取代了水杨酸的一个羟基——氧和氢与碳结合——乙酰基是两个碳，一个与氧双键结合，另一个与三个氢结合。