4Joseph Evans Grimes.The Thread of Discourse[M].The Hague Mouton publishers,1975.
5Paulston,C.B.The sequencing of structural pattern drills[A].In K.Croft (ed.),Readings on English as a Second Language.Cambridge,Mass.:Winthrop.1980.
6董文君.英语一般疑问句的话语功能.南北桥,2008,(9).
7Porter,P.A.How learners talk to each other:input and interaction in task-centered discussions[C].Paper presented at TESOL convention,Toronto,March 1983.