They become the principal supplier of grain and fish in Europe.

他们成为欧洲谷类和鱼产的主要供货商

耶鲁公开课 - 欧洲文明课程节选

You see the lactose of course from milk, and then when you get down to the cellulose, and we're talking about starches and then fiber gets involved in here too, then cereals and vegetables become the primary source of these.

你们知道乳糖来自于乳类,当你研究纤维素的时候,以及我们在这里所说的淀粉和纤维,他们最主要的来源是谷类和蔬菜

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选