问题
填空题
根据示例写单词。
例: 
lion lions
1. 
______________ ______________
2. 
______________ ______________
3. 
______________ ______________
4. 
______________ ______________
5. 
______________ ______________
答案
1. cow, cows 2. cat, cats 3. fish, fishes 4. horse, horses 5. tree, trees