将下列单词归类。
banana, twenty, rabbit, apple, tomato,
dog, twelve, onion, horse, pear, thirty,
carrot, orange, two, potato, watermelon,
fifteen, sheep, cat, cucumber
1. 水果: ____________________________
2. 蔬菜: ____________________________
3. 动物: ____________________________
4. 数字: ____________________________