Pick out the word which is stressed differently from that of the others

II. Pick out the word which is stressed differently from that of the others:

11. A. celebrate                          B. abroad                           C. vacation                       D. enjoy

12. A. souvenir                           B. sunglasses                     C. delicious                       D. holiday

13. A. wonderful                        B. exciting                         C. sightseeing                    D. postcard

14. A. famous                             B. pleasure                        C. refer                              D. answer

15. A. contest                             B. relieve                           C. affect                             D. revive