Dear Professor Liang,
I am writing to extend my gratitude to you. Because of your help，now I am a student of Chemistry Department of Sydney University.
Last June, when I applied to become a graduate student of Sydney University, you really gave me a lot of valuable help. You not only wrote a recommendation(推荐) for me to Professor Wells who works in the Sydney University，but also gave me careful and patient instructions on how to fill the application forms and write the application letters.
It is your unreserved(无保留的) help that enables me to obtain this splendid(极好的)opportunity of further education. For the following two years I will study hard to reciprocate(回报) your sincere help and expectations with excellent grades.