Dear Miss Jane,
As you are aware, I did very well in my last examination. I now wish to thank you for all the good work that you had done for me and for all the others in the class.
You must believe me when I say that we found your lessons very interesting, and your kind words were an added inspiration to us to study hard.
I am sure it was only because of your good work that I and many others in the class did so well in the examination. I shall always remember you with affection, gratitude and respect as well my friends who passed the examination together with me.
You are indeed a teacher of outstanding calibre and it is a unique privilege to be taught by you.
Yours loving student,
Ruby Nandy