Here are the answers along with explanations for each question:

### I. PHONETICS

1. **C. ethnic**
- The underlined part "e" in **ethnic** is pronounced as /ɛ/, whereas in the other words (ancestor, diverse, heritage) the "e" is pronounced as /ə/ or /iː/.

2. **D. unique**
- The underlined part "u" in **unique** is pronounced as /juː/, while in the other options (hunt, custom, multicultural) it is pronounced as /ʌ/.

3. **D. match**
- The underlined part "a" in **match** is pronounced as /æ/, whereas in the other words (shawl, gather, add), the "a" is pronounced as /ɑː/ or /ə/.

### Stress Pattern

0. **D. curious**
- The stress pattern of **curious** is different (stress on the second syllable) compared to the others (first syllable stress for minority, majority, and diversity).

0. **B. recognise**
- The word **recognise** does not have the stress on the last syllable, unlike **costume**, **significant**, and **terraced**, which have stress patterns typically on the first syllable.

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### II. VOCABULARY

0. **C. herding**
- The best fit meaning is that a boy is looking after or guiding the buffalo.

0. **D. the view**
- "the view" is the correct phrase, indicating a specific view that could be blocked.

0. **B. mountainous**
- The term "mountainous" describes an area characterized by mountains.

0. **A. diversity**
- "diversity" refers to the variety of ethnic groups present in Vietnam.

0. **B. agricultural**
- "agricultural" is the adjective that describes something related to farming or crops.

0. **A. communal**
- "communal" relates to a community and fits perfectly in the context of a house serving the tribal group.

0. **B. international**
- "international" schools are those that cater to students from different countries.

0. **C. religious**
- "religious" is the correct adjective to describe festivals connected to religion.

14. **B. preserve**
- "preserve" means to maintain or keep up the traditional cultural identities.

0. **A. tradition**
- "tradition" refers to the established custom, which fits logically in the sentence about wet rice cultivation.

Feel free to ask if you need clarification or further assistance!