Dear Professor xxxxxx，
I am glad to receive your letter and the good news to Mr xxxxxx. As his supervisor， I have known him for more than five years， and I am pleased to give you a formal statement.
Mr. xxxxxx graduated from xxxxxx University and began his Ph.D. study under my supervision in xxxxxx in xxxxxx. His research work mainly focused on xxxxxx. He was proficient in xxxxxx. Due to his hard work， a lot of progresses have been made in this years. I know that he have acquired a broad and strong experience in xxxxxx， especially in xxxxxx study.
In my close contact with him， I was deeply impressed by his strong interest and enthusiasm in scientific research. Besides， he has fine ideas and can design reasonable plans for his
research. From my observation， he can undergo a new research project independently and quickly because of his mastery of xxxxxx techniques and quickly taking in new techniques.
Furthermore， he is also modest and easy to get along with， he showed high respecting to teachers or advisors. He energetically participated in some common affairs in the lab. These characters will allow him to adapt to a new environment rapidly.
Mr. xxxxxx is one of the most studious and promising fellows among my students. I recommend him to you without any
hesitation and expected that the postdoctoral experience in your laboratory will provide further refinement and specific training for him.