Aug. 18, 1989 Dear Liu Dong, I'm back at school now. I wish to express my thanks to you for the wonderful vacation I spent with you and your family. During the vacation you taught me how to swim, boat and fish. I really appreciate your taking time off work to take me around and show me so many places. Your mother is such a terrific cook! I think I must have gained 10 pounds just in the week I spent with you. Surely I've spent a happy vacation, which will be remembered for long. I ho...