I want to find some information about the phrases about formal writing. I am preparing the test as a foreign student, so I think I need some help. Thank you very much.
Welcome to the forum, duyutong.
Your question is far too general for us to answer, I am afraid. We could write a whole book, or two, on 'formal writing'. We are happy to try to answer specific questions, but we don't have time to write books.