4Hymes,D.On communicative competence [A]. In J. Pride & J.Holmes(eds.) Sociolinguistics[C].Harmondsworth:Penguim.1972:269-293.
5Campbell,R.& Wales,R.The study of language acquisition[A].In Lyons(ed.) New Horizons in Linguistics[C].London:Penguin.1970:242-260.
6Putz,M.(ed.)Thirty Years of Linguistic Evolution[C].Amsterdam:John Berjamins. 1992.
7Quirk,R.The English language in a global context [A].In R.Quirk,& H.G. Widdiwsons(eds.) English in the World [C].Oxford University Press.1984.
8Berns, M.Context of Competence:Social and Cultural Considerations in Communicative Language Teaching [M]. New York: Plenum Press. 1990.
9Wolfson,N.Perspectives:Sociolinguistics and TESOL [M]. Philadelphia;Newbury House.1989.
10Widdowson,H.Aspects of the relationship between culture and language [A].In R. Ahrens & H.Antor(eds.) Text-Culture-Reception:Cross-cultural Aspects of English Studies[C],Heidelberg:Groos.1992.
