1开头语（问候、点明目的） How is everything going? How are you doing these days? Id like to ask you to . Ive just learned / heard that . Im writing to let you know that . I learn from your last letter that . Im sorry to say that I cannot . Id like to invite you to join us for a visit to the . I want to express my sincere thanks to you for your help. I am writing to apply to be a volunteer for . I just received your letter yesterday, and Im glad to know
