a question about drag and drop of text

Hi all, there is a problem I need your suggestion. I want to make a small app which acts like a logic test, there are several sentences on it, and the users are asked to give an better order of these sentences to make a coherence text. I think drag and drop will make the operation easier, but I am not sure which widget should be used, how to implement the drag and drop function. en.. that's it, hope I made what I need clearly enough, sorry for my poor English.