Here are the answers indicating the word that differs in the position of the main stress:

**IV. Mark A, B, C or D:**
1. **A.** suggest (stress on 2nd syllable)
2. **C.** reward (stress on 2nd syllable)
3. **D.** appeal (stress on 2nd syllable)
4. **B.** survive (stress on 2nd syllable)
5. **A.** legal (stress on 1st syllable)
6. **A.** explain (stress on 2nd syllable)
7. **B.** relax (stress on 2nd syllable)
8. **B.** obtain (stress on 2nd syllable)
9. **A.** inform (stress on 2nd syllable)
10. **B.** listen (stress on 1st syllable)

**V. Mark the primary stress on each of the following words:**
1. **Strengthen:** stress on the 1st syllable
2. **Responsibility:** stress on the 4th syllable
3. **Value:** stress on the 1st syllable
4. **Create:** stress on the 2nd syllable
5. **Reduce:** stress on the 2nd syllable
6. **Upload:** stress on the 2nd syllable
7. **Talent:** stress on the 1st syllable
8. **Housework:** stress on the 1st syllable
9. **Breadwinner:** stress on the 1st syllable
10. **Laundry:** stress on the 1st syllable
11. **Lifestyle:** stress on the 1st syllable
12. **Energy:** stress on the 1st syllable
13. **Resource:** stress on the 2nd syllable
14. **Social:** stress on the 1st syllable
15. **Result:** stress on the 2nd syllable
16. **Groceries:** stress on the 1st syllable
17. **Rubbish:** stress on the 1st syllable
18. **Carbon:** stress on the 1st syllable
19. **Organic:** stress on the 2nd syllable
20. **Sustainable:** stress on the 3rd syllable
21. **Musical:** stress on the 1st syllable
22. **Eliminate:** stress on the 2nd syllable
23. **Idol:** stress on the 1st syllable
24. **Homemaker:** stress on the 1st syllable
25. **Decide:** stress on the 2nd syllable
26. **Footprint:** stress on the 1st syllable
27. **Plastic:** stress on the 1st syllable
28. **Regular:** stress on the 1st syllable
29. **Identify:** stress on the 2nd syllable

Feel free to ask for clarification or further assistance!