裸跟鞋的英文：
mules （完全没有包裹脚后跟的部分的鞋）

Panel on the mule's back.
在骡子背上设鞍垫。

A mule is a hybrid of a donkey and a horse.
骡子是公驴和母马交配而生的杂种。

A mule have neither pride of ancestry nor hope of posterity.
骡子既无足以自豪的祖宗，亦无可以寄托希望的子孙。

A mule is a hybrid of a male donkey and a female horse.
骡子是公驴和母马交配而生的杂种动物.

They were no longer using mules and horses to plow their fields.
他们那时已不再用骡子和马来犁地了。