他们为废除奴隶制度而奔走呼号。

They campaigned for the abolition of ___slavery.

这本历史著作描述了奴隶制度的残酷境况。

The historical text describes the brutal conditions of ___slavery.

许多国家都有法律明文禁止一切形式的奴隶制度。

Many nations have laws that expressly prohibit ___slavery in all its forms.