Choose the word that has the underlined part pronounced differently

Choose the word that has the underlined part pronounced differently. 
1. A. birth            B. virus              C.bird                        
2.A. cough         B. laugh           C.  high
3. A. calorie    B. musical   C.cinema         
4. A. knocked      B. needed   .founded   
5. A. burn   B. hurt    C.future
6. A. bag    B. frog    C.original
7. A. teacher   B. heard   C.answer
8. A. helped    B. donated   C. provided
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