flour ['flaʊə] n. 面粉；粉状物质 vt. 撒粉于；把…磨成粉

Bread is products by making a dough from wheat flour and aerating this with carbon dioxide produced by yeast fermentation.
面包的生产方法是先将小麦面粉制成面团，而后使此面团充以由酵母产生的二氧化碳气体。