Jun Shan spent four weeks in a host family in the

Jun Shan spent four weeks in a host family in the USA. He really enjoyed his stay and improved his English. Now Jun is back home and is writing a letter to his host family. Read the letter. What kind of letter is it: an invitation, a complaint, a thank-you, a request?
Dear Mr and Mrs Reeves,
1) I am writing to let you know that I have arrived home safely and to thank you for your kindness during my stay with you. 1).......With you and I Will never forget you.
2) 2)... everything you did to make my stay so pleasant. Is made to feel at home. I loved my room, and I must say that Mrs Reeves cooking is amazing. My mum is going to try some of the recipes you gave me.
3) I think my English improved a lot during my stay. 3)....... was our interesting conversations during dinner in the evenings. I even understand jokes now thanks to Mr Reeves great sense of humour!
4) 4).... your generosity and your hospitality. I hope we w.U keep in touch and perhaps you could visit us one day.
Best regards,
Jun