Q

As a large horse is getting on in age,why should he alwaysstay in cold and wet？
当一匹马日渐衰老，为什么总待在又湿又冷的地方？

A

So that he could catch cold and become a little hoarse.
这样他就可以着凉，嗓子就可以有些嘶哑。

点睛一笔

hoarse是形容词，意思是“嘶哑的”，音似horse。a little horse的意思是“一匹小马”。看来老马很单纯，以为这样它就可以着凉，然后就变成一匹小马了。