4Nation,P.& waring,R.Vocabulary size,text coverage and word lists[A].In N.Schmitt & N.McCarthy (Eds),Vocabulary[C].Cambridge:Cambridge University Press,1997.
5Nagy,W.E.,Herman,P.A.& Anderson,R.C.Learning words from context[J].Reading Research Quality,1985,20(2).
6Nattinger,J.Some current trends in vocabulary teaching[A] In R.Carter and M.McCarthy (Eds).Vocabulary and Language Teaching[C].NewYork:Longman,1988.
7Nattinger,J.& J.Decarrico.Lexical Phrases and Language Teaching[M].Oxford University Press,1992.