上面酵母是活跃的发酵剂.Top yeasts are Vigorous fermenters.如果说这个种族是块面团,这些人便是发酵剂.These men have been the leaven in the lump of the race.细菌代替酵母成为新的发酵剂,有许多优点.Bacteria which was a new ferment had more advantages than yeast....

“发酵剂”的英语可以翻译为：[医] leaven ...