Many baby burros were born in the western states .

许多小美洲驴再西部各地出生了。

You herd all the burros in that thicket there .

你把所有的驴子放到那边的灌木丛中。

The burros ate grass needed for cattle .

因为它们吃掉了牛所需要的牧草。

Some people didn 't want their burros .

一些人不打算再要他们的美洲驴了。

These burros were called pack animals .

这些美洲驴被成为驮载动物。