3Arnold J. & Brown H D. A Map of the Terrain[A]. J. Arnold (ed) Affect in Language Learning[C]. Beijing: Foreign Language Teaching and Research Press,2000.
4Brown H D. Principles of Language Learning and Teaching[M](3 ed. ). NJ: Prentice Hall Regents. 1994.
5Brown H D. Teaching by Principles: Interactive Language Teaching Methodology[M]. New York: Prentice Hall Regents. 1994.
6Ellis R. The Study of Second Language Acquisition[M]. Shanghai: Shanghai Foreign Language Education Press. 1999.
7Krashen S D. Principles and Practice in Second Language Acquisition[M]. Oxford: Pergamon. 1982.
8Schumaan J H. The pidginization process: a model for second language Acquisition[M]. Roley, MA: Newbury House. 1978.
4Ellis R. The Study of Second Language Acquisition[M]. Oxford: Oxford University Press, 1994.
5Brown H D. Principles of Language Learning and Teaching [ M ]. (3^rd edition). NJ: Prentice Hall Regents,1993.35.
6Krashen S. Principles and Practice in Second Language Acquisition[M]. Oxford: Pergamon Press, 1982.
7Schumann J. The Piginization Process : A Model for Second Language Acquisition[M]. Rowly, Mass. : Newbury House, 1978.
8Guion S G, J E Flege, S H Liu, & G H Yeni-Komshian. Age of learning effects on the duration of sentences produced in a second language[J]. Applied Psycholinguistics 2000, (21): 205- 228.
9Bialystok E. The structure of age : in search of barriers to second language acquisition[J]. Second language Research, 1997,(13):116- 137.