第一部分
一、简要综述以往和现在研究：
1.It is well accepted that ...;Previously,it has been reported that ...;A previous report had shown ...;Previous studies have indicated that ...;
2.Compelling evidence in this regard is currently lacking;However, ... have yet to be fully defined;There is a urgent need to ....;some problematic disadvantages cannot be overlooked;
3.This study aims to contribute to this growing area of research by exploring
4.Recent evidence suggests that …
5.Extensive research has shown that …
6.Existing research recognises the critical role played by …
7.Surveys such as that conducted by Smith (1988) have shown that …
8.Factors found to be influencing X have been explored in several studies.
9.Studies over the past two decades have provided important information on …
10.A considerable amount of literature has been published on X. These studies …
二、重点回顾与本工作相关的研究：
1.By employing qualitative modes of enquiry, I attempt to illuminate the …
2.Qualitative and quantitative research designs were adopted to provide …
3.Both qualitative and quantitative methods were used in this investigation.
4.A holistic approach is utilised, integrating X, Y and Z material to establish …
5.The study was conducted in the form of a survey, with data being gathered via …
6.The methodological approach taken in this study is a mixed methodology based on …
7.It is beyond the scope of this study to examine the …
8.A full discussion of X lies beyond the scope of this study.
9.The reader should bear in mind that the study is based on …
10.Another potential problem is that the scope of my thesis may be too broad.
11.Due to practical constraints, this paper cannot provide a comprehensive review of…
三、以往工作不足：
1.Such expositions are unsatisfactory because they …
2.Most studies in the field of X have only focused on …
3.Such approaches, however, have failed to address …
4.Previous published studies are limited to local surveys.
5.Half of the studies evaluated failed to specify whether …
6.The research to date has tended to focus on X rather than Y.
7.Previously published studies on the effect of X are not consistent.
8.Smith’s analysis does not take account of …, nor does she examine …
9.The existing accounts fail to resolve the contradiction between X and Y.
四、回到本研究中来：
1.This research has thrown up many questions in need of further investigation.
2.A greater focus on X could produce interesting findings that account more for …
3.The issue of X is an intriguing one which could be usefully explored in further research.
4.If the debate is to be moved forward, a better understanding of X needs to be developed.
5.I suggest that before X is introduced, a study similar to this one should be carried out on …
6.More information on X would help us to establish a greater degree of accuracy on this matter.
7.An additional uncontrolled factor is the possibility that …
8.It was not possible to assess X; therefore, it is unknown if …
9.An issue that was not addressed in this study was whether…
10.The generalisability of these results is subject to certain limitations. For instance, …
11.One source of weakness in this study which could have affected the measurements of X was …
第二部分
一.为进一步的研究工作提出建议
1.A further study could assess the long-term effects of …
2.What is now needed is a cross-national study involving …
3.Considerably more work will need to be done to determine …
4.The precise mechanism of X in insects remains to be elucidated.
5.These findings provide the following insights for future research: …
6.Large randomised controlled trials could provide more definitive evidence.
7.This research has thrown up many questions in need of further investigation.
8.A greater focus on X could produce interesting findings that account more for
二.提供与以前研究相矛盾的比较结果的解释
1.This finding is contrary to previous studies which have suggested that …
2.In contrast to earlier findings, however, no evidence of X was detected.
3.The yields in this investigation were higher compared to those of other studies.
4.However, the findings of the current study do not support the previous research.
5.Smith et al. (1999) showed that … This differs from the findings presented here …
6.The overall level was found to be 15%, lower than that of previously reported levels.
7.It has been suggested that … (Smith et al., 2002). This does not appear to be the case.