Trọng âm Exercise IV: Mark the letter A, B, C or D to indicate the word that differs from the other three in the position of primary stress in each of the following questions. 1. A. doctor B. address C. thermal D. visual 2. A. wonderful B. permanent C. aquatic D. physicist 3. A. awesome B. precise C. forest D. accent 4. A. attractive B. balcony C. chocolate D. decorate 5. A. musical B. headmaster C. engineer D. humorous 6. A. quality B. messenger C. natural D. pagoda 7. A. practice B. starter C. afford D. vary 8. A. alternate B. cultural C. televise D. semester 9. A. welcome B. become C. canteen D. upstairs 10. A. afternoon B. universe C. estimate D. versatile