I am writing this letter to express my sincere gratitude for___________.Had it not been for your assistance in ___________,I fear that ___________may not have____________.Id like you to know that your help __________.It not only____________,but also__________.I shall always remember__________.

I hope that I will have the opportunity of returning your hospitality by inviting you to ______.Will you kindly let me know whether you____________?I am looking forward to seeing you soon!