Translation of vindictive in Spanish

OK, I've understood the overall picture. I'm a little doubtful about how to detect the copyright issues, but I guess it's better to talk again after I received the first excel sheet. It is alright, I am seeing it as an extra measure.
It certainly is one of the reasons that a student from abroad is not as good in English as people who were born in America. This is an obstacle for all students and a challenge for the educational system.
When I flew to Korea, I was very nervous because this was the first time I had visited a country outside the European Union. Asia is far away for us and is culturally very different.