是省略,表示补充说明-》 It is the number, kind , and arrange of teeth that determine whether a mammal is classified as a carnivore not the food that the animal acctually eats. ->the number, kind , and arrange of teeth determine whether a mammal is classified as a carnivore not the food that the animal acctually eats ->the number, kind , and arrange of teeth determine whether a mammal is classified as a carnivore and the food that the animal acctually eats can't determine whether a mammal is classified as a carnivore. 不知道你还记得以前有个题是考 if not +adj,是一个道理 你说的省略and是绝对不可能的  |