Introductory sentences 

• The topic/issue/subject I want to talk about ...
• The paper/articlediscusses/deals with/analyses/considers/explains/describes/establishes/introduces .....
•  develops/presents/provides/studies/represents/features/contains/concentrates on ..... 
• covers/suggests/proposes/shows .....
  
• demonstrates the feasibility of .....
  
• opens up a new field/issuegives/aims to give a comprehensive account of ..... 
  
• offers a solution to .....
  
• serves as an introduction to .....
  
• The main objective/goal/purpose of the paper/article is ...
• http://en.fel.zcu.cz/AE%20III%20Guidelines%20for%20Academic%20Writing/How%20to%20write%20a%20paper/Useful%20phrases.pdf
  

Beispielsätze:

• https://lehrerfortbildung-bw.de/faecher/englisch/bs/2bfs/cellphone/09\_discussion.html

"rating teachers online":

• http://www.mlive.com/opinion/kalamazoo/index.ssf/2009/09/our\_turn\_should\_students\_be\_al.html