So, are you from Rio Grande do Sul, Santa Caterina or Paraná?!
Here’s the thing: you are asking a US university to gift you ~$300,000 of education. There are many, many people- both in the US and around the world- who would like a free degree from Yale, Penn or Duke.
You are asking them to do that with one objective piece of information (your IELTS/TOEFL/DATS score), or possibly two (SAT/ACT, which are optional for 2022 entry), and one piece of evidence about your academic ability (your transcript). The rest is your essays, your LoRs, and ECs.
All three schools turn down more than 90% of applicants, and international students make up around 10% of those admitted. So, in round numbers, that’s a 1% acceptance rate.
Has your school ever sent a student to any of these schools? to any US school?
Will your advisor say that you are primus inter pares in your school, and back it up with examples of how extraordinary your are?