Dear

How are you doing? Thanks for the recent invitation, but unfortunately I’m afraid I won’t be able to come to your 21st birthday party. I have an important exam at the same day and I can’t miss it. If I pass this exam, I will have a chance to study in abroad.

I’m very busy recently. It is difficult for many things to be finished in 24 hours because having a lot of things I must do.I study hard to prepare for the exam. I also take part in a club about protecting environment with some mates. My club has many beneficial activities for students. Do you want to join it?

I will finish my exam in this time next week. So, why don’t we meet up to catch up on our news? I want to invite you to have a café at the cafeteria we often meet. If you don’t busy, we will meet each other on Thursday next week.

Anyway, I must get down to study again. So, thanks again for the invitation and I’m really sorry I will have to miss it. Please tell me about some interesting things in the party. I guest they quite exciting.

All the best