Hi all, I would like to paraphrase the following sentence because it seems a bit clumsy to me: The primary goal of our work is to present the change that took place at the end of the twentieth century and beginning of the twenty-first century. I've thought of a solution: The primary goal of our work is to present the change that took place at the turn of the twentieth and the twenty-first century/ies. What do you think of my solution? Is it acceptable or shall I improve it somehow? And should I write century or centuries? Thanks a lot!