1.这是一句谚语吧

用a的是：horse、bull、cow

用an的是：ox

都是形容非常健壮

PS:

1. as bald as a coot头发脱光的（像黑鹅一样秃）

2. as blind as a bat 有眼无珠（像蝙蝠一样瞎）

3. as blind as an owl 瞎透了（像猫头鹰一样瞎）

4. as bold as brass 厚颜无耻（像黄铜一样厚脸皮的）

5. as busy as a bee 极忙碌（像蜜蜂一样忙碌）

6. as clear as a bell 健全的（像铃铛一样健全）

7. as clear as day 一清二楚的（像白天一样清楚）

8. as cool as a cucumber 极为冷静的（像黄瓜一样冷静）

9. as easy as a pie 极容易（像馅饼一样容易）

10. as fussy as a hen with one chick 在小事上瞎操心

11. as hard as the nether millstone 铁石心肠（像下层的磨石坚硬）

12. as hungry as a hunter 非常饥饿（像猎人一样饥饿）

13. as lively as a cricket 极活泼（像蟋蟀一样活泼）

14. as mad as a wet hen 非常生气（像弄湿的母鸡一样生气）

15. as mild as a dove 非常温和（像鸽子一样温和）

16. as plain as the nose in your face 一清二楚（像你脸上的鼻子一样清楚）

17. as poor as a church mouse 赤贫的（像教堂的老鼠一样穷）

18. as proud as a peacock 极骄傲（骄傲得像只孔雀）

19. as strong as a horse 健壮如牛

20. as stupid as an owl 极愚蠢（像猫头鹰一样愚蠢）

21. as thin as a wafer极薄（像糯米纸一样薄）

22. as true as steel 绝对可靠（像钢一样可靠）

希望帮助到你！

2.英语的谚语故事

A BAT who fell upon the ground and was caught by a Weasel pleaded to be spared his life. The Weasel refused, saying that he was by nature the enemy of all birds. The Bat assured him that he was not a bird, but a mouse, and thus was set free. Shortly afterwards the Bat again fell to the ground and was caught by another Weasel, whom he likewise entreated not to eat him. The Weasel said that he had a special hostility to mice. The Bat assured him that he was not a mouse, but a bat, and thus a second time escaped. It is wise to turn circumstances to good account.。