5[4]Vygotsky, L. 1962.Thought and Language[M]. Cambridge,MA:MIT Press.
6[6]Richard, J, J.Platt, and H.Weber. 1986.Longman Dictionary of Applied Linguistics. London: Longnan.
7[7]Breen, M.1987.Learner contributions to task desiga. In C. Cadlin and D. Murphy ( eds. ) Language learning Tasks,. [ C ]. Englewood Cliffs NJ: Prentice Hall.
8[8]Scovel T. The effect of affect on foreign language learning: A review of anxiety research [ J ]. Language Learning, 1987.
9Bialystok, E. A Theoretical Model of Second Language Learning. Language Learning. New York: Academic Press, 1978.28.
10Catherine Twomey Fosnot. Constructivism : Theory, Perspectives, and Practice [M]. Teachers College Press, 1996.
