Sure! Let's address the first task regarding the words with different stress patterns.

1. **1st Set:**
- A. consumption (stress on second syllable)
- B. explosion (stress on second syllable)
- C. technician (stress on the second syllable)
- D. mathematician (stress on the fourth syllable)

**Different Stress Pattern: D. mathematician**

2. **2nd Set:**
- A. magician (stress on the second syllable)
- B. vegetarian (stress on the fourth syllable)
- C. historian (stress on the second syllable)
- D. civilian (stress on the second syllable)

**Different Stress Pattern: B. vegetarian**

3. **3rd Set:**
- A. procession (stress on second syllable)
- B. companion (stress on second syllable)
- C. production (stress on second syllable)
- D. celebration (stress on the third syllable)

**Different Stress Pattern: D. celebration**

4. **4th Set:**
- A. magician (stress on second syllable)
- B. vegetarian (stress on the fourth syllable)
- C. historian (stress on the second syllable)
- D. civilian (stress on the second syllable)

**Different Stress Pattern: B. vegetarian**

5. **5th Set:**
- A. confusion (stress on second syllable)
- B. musician (stress on the second syllable)
- C. ancestor (stress on first syllable)
- D. importance (stress on the second syllable)

**Different Stress Pattern: C. ancestor**

6. **6th Set:**
- A. tradition (stress on second syllable)
- B. festival (stress on the first syllable)
- C. emperor (stress on the first syllable)
- D. motherland (stress on the first syllable)

**Different Stress Pattern: A. tradition**

7. **7th Set:**
- A. clinician (stress on second syllable)
- B. pagoda (stress on the second syllable)
- C. visitor (stress on first syllable)
- D. arrival (stress on the second syllable)

**Different Stress Pattern: C. visitor**

8. **8th Set:**
- A. librarian (stress on the second syllable)
- B. physician (stress on the second syllable)
- C. Brazilian (stress on the second syllable)
- D. Indonesian (stress on the third syllable)

**Different Stress Pattern: D. Indonesian**

Now, let’s move on to the second task concerning the pronunciation of underlined parts:

1. **1st Set:**
- A. festival (e)
- B. man (a)
- C. fat (a)
- D. grand (a)

**Different Pronunciation: A. festival**

2. **2nd Set:**
- A. upset (u)
- B. custom (u)
- C. museum (u)
- D. unsuitable (u)

**All have similar pronunciations; however, the "n" in custom makes it sound different, so possible answer: B. custom**

3. **3rd Set:**
- A. saint (ai)
- B. tailor (ai)
- C. explain (ai)
- D. said (e)

**Different Pronunciation: D. said**

4. **4th Set:**
- A. beach (ea)
- B. catch (a)
- C. church (u)
- D. Christmas (is mass)

**Different Pronunciation: A. beach**

Please note that in some sets, the differences may be subtle.