奴隶的生活十分艰苦而残酷。

Núlì de shēnghuó shífēn jiānkǔ ér cánkù.

The life of a slave was extremely difficult and cruel.

废除奴隶制度是社会的进步。

Fèichú núlì zhìdù shì shèhuì de jìnbù.

Abolishing the system of slavery is social progress.

在古罗马时代，奴隶是社会底层的人。

Zài gǔ Luómǎ shídài, núlì shì shèhuì dǐcéng de rén.

In ancient Rome, slaves were the lowest class in society.