Choose the word whose underlined part is pronounced differently from the others

I. Choose the word whose underlined part is pronounced differently from the others.
1. a. laugh b. cough c. bought d. tough
2. a. game b. gym c. girl d. bag
3. a. calorie b. labour c. community d. volunteer
4. a. environmental b. benefit c. service d. sick
5. a. danced b. helped c. watched d. enjoyed
Gấp! Gấp! Giúp mik với nhưng nhớ ghi phần âm của đáp án đấy nữa><