The BBC World Service broadcasts by radio worldwide, using English and 37 other languages, for 820 hours a week. The main objectives are to give unbiased news, reflect British opinion and project British life, culture and developments in science and industry. News bulletins, current affairs programmes, political commentaries and topical magazine programmes form the main part of the output. These are supplemented by a sports service, music, drama and general entertainment. Regular listeners are estimated to number 120 million. The languages in which the World Service broadcasts and the length of time each is on the air are prescribed by the Government. Otherwise the BBC has full responsibility and is completely independent in determining the content of news and other programmes. There are broadcasts by radio for 24 hours a day in English, supplemented at peak listening times by programmes of special interest to Africa, East Asia, South Asia, Europe, the Caribbean and the Falkland Islands. BBC World Service news bulletins and other programmes are re-broadcast by some 45450 radio and cable stations in over 80 countries, which receive the programmes by satellite. Two World Service departments also specialise in supplying radio material for re-broadcast. BBC transcription sells recordings to more than 100 countries, while BBC Topical Tapes airmails some 250 tapes of original programmes to subscribers in over 50 countries each week. BBC English is the most extensive language-teaching venture in the world. English lessons are broadcasted daily by radio with explanations in some 30 languages, including English, and re-broadcast by many radio stations. BBC English television programmes are also shown in more than 90 countries. A range of printed, audio and video material accompanies these programmes. Another part of the World Service, BBC Monitoring, listens to and reports on foreign broadcasts, providing a daily flow of significant news and comment from overseas to the BBC and the Government. This information is also sold to the press, private sector companies, academic staff and public bodies.