1. Child – children

1.孩子

2. Man – men

2.男人

3. Datum – data

3.数据

4. Criterion – criteria

4.标准

5. Medium – media

5.媒质

6. Foot –feet

6.脚，英尺

7. Tooth – teeth

7.牙齿

8. Mouse – mice

8.老鼠

9. Sheep – sheep

9.羊

10. Crisis – crises

10.危机

11. Stimulus – stimuli

11.刺激

12. Thief – thieves

12.贼，小偷

13. Wolf – wolves

13.狼

14. Leaf – leaves

14.叶子

15. Person – people

15.人

16. Life – lives

16.生命

17. Goose – geese

17.鹅

18. Thesis - theses

18.主题

19. Potato – potatoes

19.土豆

20. Cactus – cacti

20.仙人掌