2Spada, N. 1997. Form-focused instruction and second language acquisition : A review of classroom and laboratory research[J ]. Language Teaching 29 : 1-15.
3Swain, M. 1985. Communicative competence: Some rules of comprehensible input and comprehensible output in its development [A]. In S. Gass & C. Madden (eds.). Input in Second Language Acquisition[C]. Rowley, MA: Newbury House.
4Swain, M. 2000. The output hypothesis and beyond: Mediating acquisition through collaborative dialogue [A]. In J. P. Lantolf (ed.). Sociocultural Theory and Second Language Learning [C]. Oxford: Oxord University Press.
5van den Branden. K. 1997. Effects of negotiation on language learners' output[J]. Language Learning 47: 589-636.
6van Patten, B. 2002. Processing instruction: An update [J]. Language Learning 52: 755-803.
7Wajnryb, R. 1990. Grammar Dictation [M]. Oxford:Oxford University Press.
8Widdowson, H. G. 1978. Teaching Language as Com.munication [ M]. Oxford. Oxford University Press.
9White, J. 1998. Getting the learners' attention: A typographical input enhancement study [A]. In C. Doughty & J. Williams(eds. ). 1998.
10Bolinger, D. 1977. Meaning and Form [M]. London: Longman.