read four papers provided below and feel free to use the figures from the papers for easier explanations. Need to be good academic language (grammar, spelling and good flow) and use references (citations) you can also compare the papers, but make sure to answer these questions for each paper:
1. for the paper:
* what is it about?
* what did the researcher attempt to do?
* why and how did they do it?
* how was the result?