How well do you know what these letters stand for?

ESL

UFO

ETA

ESL - English as a second or foreign language is the use of English by speakers with different native languages. (Английский, как второй язык для говорящих на разных своих языках)

UFO - НЛО (Unknown Flying Object)

UFO - are an English rock band that was formed in London in 1969.

They became a transitional group between early hard rock and heavy metal and the new wave of British heavy metal.

Eta (Η, η) - is the seventh letter of the Greek alphabet.

ETA - Estimated time of arrival - ожидаемое время прибытия.

ETA Systems - компания по производству суперкомпьютеров.