Let us take an example from the nineteenth century, which was a time when the world was successful in initiating the process of completely eradicating the age-old practice of slavery, which had until then been considered to be natural and immutable.
我们举一个十九世纪的例子， 当时，世界成功地彻底消除了古老的奴隶制，而在此之前，奴隶制一直被认为是自然的、不可动摇的。