Choose the word whose the underlined part is pronounced differently

I. Choose the word whose the underlined part is pronounced differently.
1. a.structure         b.sugar          c.lunch         d.sun 
2. a.population      b.from            c.shop          d.tower 
3. a.capital            b.thick            c.high           d.million 
4. a.desert            b.exercise       c.few            d.French 
5. a.bread             b.speak           c.ahead       d.breakfast