Here are the odd ones out from each of the exercises:

**Exercise 3: Circle the odd one out.**
1. **A: second** (B: village, C: third, D: first - these all refer to ordinal numbers)
2. **A: computer room** (B: art room, C: Vietnamese, D: music room - these all are types of rooms related to subjects)
3. **C: Malaysia** (A: teacher, B: doctor, D: writer - these all refer to occupations)
4. **C: draw** (A: friendly, B: read, D: sing - these can be actions; 'friendly' is an adjective)
5. **C: sometimes** (A: rarely, B: never, D: floor - 'floor' is not an adverb of frequency)

Let me know if you need any more help!