Dear Sally, We are having a wonderful time (15) ……… the USA. The (16) ……… are friendly and the (17) ……… has been warn and sunny. In San Francisco, I (18) ……… my friends, Sandra Smith and (19) ……… family. It was (20) ……… to see them. I (21) ……… lost of souvenirs (22) ……… the children. Thanh is always complaining about the (23) ……… of my suitcase. See you (24) ………… Love, Quyen. 15. A. of B. on C. in D. at 16. A. boy B. student C. friend D. people 17. A. picture B. weather C. people D. summer 18. A. visiting B. visited C. to visit D. visits 19. A. her B. them C. him D. you 20. A. loving B. lovely C. love D. to love 21. A. is bought B. to buy C. bought D. has bought 22. A. between B. on C. to D. for 23. A. heaviness B. heavily C. heavy D. heaviness 24. A. on B. last C. soon D. so