感谢信
    当别人帮了你一个忙时，你应该给他写封信，以示感激。
Dear John:
    Thank you very much for the nice birthday present you have sent me! I have been longing for a dictionary for a long time. It will surly be very helpful to my study.
    It's very nice of you to remember my birthday, I'll make good use of the dictionary and I'll think of you with gratitude and affection every time I use it.
                                                                                                                           Love,
                                                                                                                            Sally