Dear Fred,
I have been thinking since you asked me for " help " two days ago. At last I decide to write to you.
I think the test is a test of their studying level, no need to ask someone for help. You should have a good review, and in the two cycle of the exam, I still have time. You know that you are not better study.
The day that I refused you, our relationship seems embarrassed. I don't want to lose you as a good friend, hope we can keep the friendship. At the same time, wish you to test a good result.
Let's be good friends forever and Iwish you good luck in the exam.
yours sincerely,
Tom