I.Choose the word which has the underlined part pronounced differently from the others. 1. A. twice B. flight C. piece D. mind 2. A. about B. around C. sound D. young 3. A. cover B. oven C. coffee D. company 4. A. plates B. cakes C. mates D. places 5. A. laughed B. learned C. changed D. arrived 6. A. definition B. electricity C. contaminate D. radiation 7. A. dramatic B. overhead C. century D. groundwater 8. A. thermal B. beneath C. rubbish D. earplug 9. A. affect B. billboard C. visual D. substance 10. A. aquatic B. behavior C. pollution D. permanent