假如你是betty,你接到了你的同学mary的邀请,去参加他星期六的生日晚会.你很想去,假如你是betty,你接到了你的同学mary的邀请,去参加她星期六的生日晚会.你很想去,但是你要看医生、上钢琴课

假如你是betty,你接到了你的同学mary的邀请,去参加他星期六的生日晚会.你很想去,假如你是betty,你接到了你的同学mary的邀请,去参加她星期六的生日晚会.你很想去,但是你要看医生、上钢琴课
假如你是betty,你接到了你的同学mary的邀请,去参加他星期六的生日晚会.你很想去,
假如你是betty,你接到了你的同学mary的邀请,去参加她星期六的生日晚会.你很想去,但是你要看医生、上钢琴课、做作业、照看妹妹.等很多事.请用英文写封信并回绝她,祝她玩得高兴.100词!拜托了

假如你是betty,你接到了你的同学mary的邀请,去参加他星期六的生日晚会.你很想去,假如你是betty,你接到了你的同学mary的邀请,去参加她星期六的生日晚会.你很想去,但是你要看医生、上钢琴课
Dear Mary,
Thanks for inviting me to your birthday party.I would like to join you very much,but there are a lot of things for me to deal with.Fisrt,I have to go to see the doctor,becauseI have had a headache for two days.Then, I will have a piano lesson.After dinner,I must finish my homework.What is more, I have to take care of my little sister while my mother is sleeping.Though I can not join you ,I wish you a happy night,
Yours,Betty