情景：快放暑假了，妈妈让你给上海的爷爷奶奶写一封信。
任务：请你用英语给爷爷奶奶写一封50左右的短信。内容包括：
      1 向他们问候； 2 你在学校的情况如何； 3 你暑假打算做什么。      请用下面格式：
Dear grandma and grandpa ,
  ……
                                                          Mimi
范文：
Dear grandpa and grandma ,
  How are you ?
  I’m doing well at school now . My father and mother are pleased with my marks . Of all the subjects . I like maths best . I’m also interested in English . Our summer holiday begins on the fourth of July . I want to spend the holiday with you , and my parents agree with me . Now I’m looking forward to seeing you again .
                                                           Mimi