Let's go through the provided sentences and choose the best answers:

**17. Joe: "Do you think this shirt looks good on me?" - Kevin**
- The most appropriate response is:
**B. I think you should try another one.** (This is a more fitting reply to Joe’s question about how he looks in the shirt.)

**Mark the letter A, B, C or D to indicate the underlined part that needs correction in each of the following questions.**

**18. Unless you don't take the pills, you won't feel any better**
- The incorrect part is:
**A. don't take** (The correct phrase should be "Unless you take the pills...")

**19. Would you mind if I take the seat next to you?**
- The incorrect part is:
**C. take** (The correct form should be "Would you mind if I took the seat...")

**20. I suggested that Blaine presenting his project in the meeting on Sunday**
- The incorrect part is:
**B. presenting** (The correct form should be "I suggested that Blaine present his project...")

**Mark the letter A, B, C or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.**

**21. Everyone just sits in front of the TV for entertainment**
- The closest meaning is:
**C. enjoyment** (Entertainment is indeed related to enjoyment.)

**22. As Christmas gets closer, the shops are full of people**
- The closest meaning is:
**C. crowded** (Full of people is synonymous with crowded.)

**Mark the letter A, B, C or D to indicate the word OPPOSITE in meaning to the underlined word in each of the following questions.**

**23. Floods and earthquakes are known as natural disasters.**
- The opposite meaning is:
**A. man-made** (Natural disasters are contrasted with human-made disasters.)

**24. Our local restaurant has very convenient opening hours.**
- The opposite meaning is:
**B. inconvenient** (Convenient is opposite to inconvenient.)

**Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks.**

**25. It (___) that Phu Quoc Island is a tropical paradise of Vietnam.**
- The correct answer is:
**A. is said** (This is the correct passive construction.)

**26. The most famous food of Phu Quoc is fish sauce, which (___) quite popular all over Vietnam and the world for decades.**
- The correct answer is:
**D. has become** (This indicates that the popularity started in the past and continues to the present.)

**27. Besides, another thing worth (___) there is the spicy but interesting black pepper.**
- The correct answer is:
**D. to try** (The phrase “worth to try” is grammatically correct; however, the more common phrasing would be "worth trying.")

So, summarizing all the answers:

17 - B
18 - A
19 - C
20 - B
21 - C
22 - C
23 - A
24 - B
25 - A
26 - D
27 - D

If you have any more questions or need further assistance, feel free to ask!