9Sapir E. The status of linguistics as a science[M]//润清.现代语言学名著选读.北京:测绘出版社,1998:188.
10Widdowson H G. English for specific purposes: criteria for course design[ C]//Selinker L, Tarone E, Hanzedi V. English for Academic and Technical Purposes: Studies in Honor of Louis Trimble. New York: Newbury House,1981 : 2.