酵母

例句：

1. 1. Yeast is a common ingredient in bread and pastries.
   酵母是面包和糕点中常见的成分。
2. 2. The brewer used a mixture of yeast and water to make beer.
   酿酒师使用酵母和水混合物制作啤酒。
3. 3. Yeast fermentation is the process by which yeast converts sugar into alcohol and carbon dioxide.
   酵母发酵是将酵母将糖转化为酒精和二氧化碳的过程。