For many years many history books claimed that “ columbus discovered america “ . why do you think native americas might disagree with the word discovered in this statement ? what might be a better word ?

Well, Columbus never actually came to America. His ship made land in the Bahamas and Cuba. He thought these islands were Asian islands because the people of Spain were unaware of the Americas, and so he wanted gold. He returned to his country and came back with more men. And killed a lot of people.
Anyway, for the sake of the American education system, I'm assuming the word the teacher is wanting is something like "recognized".

Earthquake fault lines. map above represent