Chymosin used traditionally in cheese making is an aspartic protease extracted form abomasum of suckling calves.传统干酪加工中使用的凝乳酶是从犊牛皱胃中提取出的一种天冬氨酸蛋白酶.We watched the cow suckling her calves.我们看了奶牛如何给小牛喂奶。a cow suckling her ca...