Answer:
The sentence that expresses a celebratory message happens to be:
We have triumphed in the efforts to implant hope in the breasts of millions of our people.
Step-by-step explanation:
The above sentence is celebratory sentence because, Mandela was trying to let the South Africans to know that the dark days of Apartheid are over and there is a great hope that, things would definitely get better.
That, all South Africans, would be treated just and fair irrespective their skin color.To him, the inalienable rights to human dignity cannot be over-emphasized as it should be guaranteed to all South Africans.