Which letters are the following sentences taken from?

A. A letter of complaint
B. A letter of application
C. A personal letter
D. A letter of advice
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1. It was definitely the best holiday I`ve ever had.
2. I am writing to apply for the post of junior manager.
3. We are very happy and we hope you and Martin will visit us soon.
4. Well that`s all my news for now. Write back soon.
5 I am patient, cheerful and organized.
6. I hope these suggestions will be of help to you.
7. I find this kind of service unacceptable.
8. I have enclosed a detailed CV as well as a reference letter from my previous employer.
9. I have studied English for 6 years.
10. I would like a refund or another game, otherwise there will be trouble