6Hudson, R.A. 1980. Sociolinguistics [M].Cambridge : Cambridge University Press.
7Leech, G. 1981. Semantics [M].Harmondsworth: Pen- guin Sociology of Language,Mouton & Co, The Hague, ( 1 ) : 152-216.
8W. Labov 1971.The Study of Language in its Social Context [J]. J.A. Fishman,Advances in the Sociol- ogy of Language, Mouton & Co, The Hague, ( 1 ) : 152-216.