1、Traditionally, rennet was obtained from the stomachs of young calves.
传统上，用于制作奶酪的凝乳酶是从幼牛的胃中提取的。
2、The rennet is added to the milk to coagulate it and form curds.
凝乳酶被加入牛奶中，使其凝固并形成凝块。