Here's the breakdown for the exercises:

### Exercise 1: Find the word with a different sound in the underlined part.

1. **A. bird** - /ɜːr/
- **B. girl** - /ɜːr/
- **C. first** - /ɜːr/
- **D. sister** - /ɪ/
- **Answer:** D. sister

2. **A. burn** - /ɜːr/
- **B. sun** - /ʌ/
- **C. hurt** - /ɜːr/
- **D. turn** - /ɜːr/
- **Answer:** B. sun

3. **A. nurse** - /ɜːr/
- **B. picture** - /ɪ/
- **C. surf** - /ɜːr/
- **D. return** - /ɜːr/
- **Answer:** B. picture

4. **A. neighbor** - /eɪ/
- **B. favorite** - /ɪ/
- **C. culture** - /ʌ/
- **D. tourist** - /ʊ/
- **Answer:** A. neighbor

5. **A. hobby** - /ɒ/
- **B. hour** - /aʊ/
- **C. hotel** - /ə/
- **D. hot** - /ɒ/
- **Answer:** B. hour

### Exercise 2: Find the word which has different stress from the others.

1. **A. arrange** - stress on second syllable
- **B. foreign** - stress on first syllable
- **C. lyric** - stress on first syllable
- **D. model** - stress on first syllable
- **Answer:** A. arrange

2. **A. collect** - stress on second syllable
- **B. defeat** - stress on second syllable
- **C. nature** - stress on first syllable
- **D. unique** - stress on second syllable
- **Answer:** C. nature

3. **A. receive** - stress on second syllable
- **B. perceive** - stress on second syllable
- **C. present** - stress on first syllable
- **D. arrange** - stress on second syllable
- **Answer:** C. present

4. **A. decorate** - stress on first syllable
- **B. melody** - stress on first syllable
- **C. valuable** - stress on first syllable
- **D. opponent** - stress on second syllable
- **Answer:** D. opponent

5. **A. protect** - stress on second syllable
- **B. photo** - stress on first syllable
- **C. patient** - stress on first syllable
- **D. nature** - stress on first syllable
- **Answer:** A. protect

### Summary of Answers:
- **Exercise 1:** D, B, B, A, B
- **Exercise 2:** A, C, C, D, A