다음 문장에서 틀린 곳이 어디인가요 가르쳐 주시면 감사하겠습니다.
every year, thousands of young people come to great britain to learn english. they come from a variety of backgrounds, and have varying expectations of how their stay in the country will be like.
(중략)
on top of that, the school should provide the students with efficient material to work with.
lastly, the school ought to try to keep up with technological developments in language learning in order to be able to offer
thses facilities to students.

위 세 곳중 하나가 틀린 것 같은데 잘 모르겠네요 ;;to be같기도 한데요..