Here are the answers marked for each item:

**I. Mark letter A, B, C or D to indicate the word whose underlined part is pronounced differently from:**
1. **C. head** (the underlined part "ea" is pronounced differently)

**II. Mark letter A, B, C or D to indicate the word whose main stress position is placed differently from:**
2. **C. celebrate** (the stress is on a different syllable)

**III. Mark the letter A, B, C or D to indicate the word OPPOSITE in meaning to the underlined word in the following question:**
5. **D. accept** (the opposite of "punish" in this context)

**IV. Mark the letter A, B, C or D to indicate the word CLOSEST in meaning to the underlined word in:**
7. **B. interested** (closest to "made up your mind")
8. **D. bored** (closest to "let down")

**V. Mark letter A, B, C or D to indicate the correct word or phrase to complete each of the following:**
9. **A. direct** (face to face)
10. **C. applicant** (when her application was refused)
11. **A. attend** (students to listen to their teacher)
12. **B. the sky’s the limit** (expressing unlimited potential)

Feel free to ask if you need any further assistance!