In the recent years, lexical chunks have gradually become a hot topic in second language teaching and acquisition. Some scholars have made comprehensive analyses of lexical chunks from the angle of cognitive theories and structures(Zheng Youqi, Xu Xianwen, 2007:33-38). Since Duan Shiping(2008), studies of lexical chunks have shifted from introduction of theories into practical researches and views and contents of these researches have gradually been enriched. These practical researches mainly focus on two aspects: (1) exploring the relationship between the acquisition of second language lexical chunks and the command of the whole language; (2) probing into the characteristics of the way that second language learners use lexical chunks. These researches, to great extent, enhance our understanding of theories of second language lexical chunks and their acquisition. 英语专业学生议论文写作中词块类型的调查研究(3):http://www.youerw.com/yingyu/lunwen_13227.html