choose the correct letter to indicate the word that differs from the other three in the position of primary stress
1 A. invention B.computer C.holiday D. detective
2 A. internet B.attention C.invention D.advantage
3 A.average B.document C.computer D.everything
4 A. grandfather B.afternoon C.library D.photograph
5 A.favourite B.tradition C.family D.exercise
6 A.banana B.january C.century D.syllable
7 A.volunteer B.engineer C.vietnamese D.holiday
8 A.opinion B. energy C.customer D.telephone