3Coleman, H. Language Learning in Large Classes Research Project[M] .Leeds and Lancaster Universities, 1989.
4Harmer, J. How to Teach English [M].Addison Wesley Longman Limited,1998.
5Ur, P. A Course in Language Teaching: Practice and Theory [M].Cambrkdge University Press, 1996.
6Vetdon, K. OFSTED Finds No Clear Link Between Class Size and Lesson Quality. Office for Standards in Education(OFSTED)hampshire County Council, 1995.http://www.coi.gov.uk:80/coi/depts./GOS/coi2431b.ok