1. 研究目的与意义（文献综述包含参考文献）

there have been many researches on the subject of oral output in linguistics both home and abroad. previous literature focuses on pauses in oral tasks includes theoretical studies and empirical ones. this literature review consists of three parts: influential definitions of oral fluency, the definition and classification of pauses and focuses of empirical studies on pauses.

1. theoretical studies on pauses

1.1 definitions of l1 and l2 oral fluency

2. 研究的基本内容、问题解决措施及方案

the study intends to compare and find out the features of the pauses in the oral output of talking on a given topic performed by chinese english majors with different language proficiency levels. the present study aims to answer the following questions:

do chinese english majors at different language proficiency levels give different performances in spontaneous speech in terms of frequency, distribution, and length of fluent runs?

this research will employ the following indices to observe pauses: speaking rate (sr) raised by towell, et al. (1996), mean length of run ( mlr) and average length of pause (alp).