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.

在古代，奴隶制度是普遍存在的。

Zài gǔdài, núlì zhìdù shì pǔbiàn cúnzài de.

In ancient times, the system of slavery was widespread.

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.