Answer:
1.explaining the oppression black South Africans had faced for decades.
2.showing the parallel between apartheid in South Africa and the Civil Rights movement.
3.emphasizing the contrast between those who were victims and those who were not .
4.making an appeal to all for basic human decency in race relations.
Step-by-step explanation:
in fact all the points are rhetorical techniques used in Mandela's Noble peace prize acceptance.