Find the word which has a different sound in the underlined part
----- Nội dung ảnh -----
Find the word which has a different sound in the underlined part.
1. A. surf
B. roof
C. of
D. father
2. A. laugh
B. though
C. cough
D. enough
3. A. machine
B. chemical
C. Christmas
D. backache
4. A. chin
B. architect
C. mechanic
D. headach
5. A. rough
B. fast
C. although
D. ferry