2Appel, G. and Lantolf, J. Speaking as Mediation: A Study of L1 and L2 Text Recall Tasks [ J ]. The Modem Language Journal, 1994, ( 78 ) :437 - 52.
3Brown, G. & Yule,G. Teaching the Spoken Language[M].Cambridge : Cambridge University Press, 1983.
4Coughlan, P. , and Duff, P. Same Task, Different Activities: Analysis of a Second Language Acquisition Task from an Activity Theory Perspective [ A ]. In J. P. Lantolf and G.Appel (Eds.) : Vygotskian Approaches to Second Language Research ( pp. 173 - 193 ) [ C ]. Norwood, NJ : Ablex,1994.
5Cummins, J. & Sayers, D. Brave New Schools : Challenging Illiteracy[M]. NY. St. Martin's Press,1997.
6Long, M. H. Input and Second Language Acquisition[ A].In Gass, S. M. & C. Madden (Eds.): Input in Second Language Acquisition [ C ]. Rowley, MA : Newbury House,1985.
7Long, M. H. The Role of the linguistic Environment in Second Language Acquisition[ A]. In Ritchie, W. C. & T. K.Bhatia (Eds.) : Handbook of Second Language Acquisition[C]. San Diego, CA: Academic Press,1996.
8Meskill, C. Computers as Tools for Sociocollaborative Language Learning[Z]. In Cameron, K. CALL: Media Design and Application. The Netherlands: Swets & Zeitlinger,1999.
9Meskill, C. & Mossop, J. Technologies Use with ESL Learners in New York State: Preliminary Report[ Z]. Report Series 3. 13. Albany, NY: National Research Center on English Learnig and Achievement, University at Albany,1997.
10Skehan, P. A Cognitive Approach to Language Teaching[ M ]. Oxford University Press, 1998.
