Here are the answers to the questions:
46. A. John is fond of participating in traditional festivals in Viet Nam.
- "Enjoy" and "be fond of" have similar meanings, both expressing liking or pleasure in something.
47. B. Mr Hung speaks English more quickly than Mr Trung.
- This sentence correctly uses the comparative form of the adverb "quickly."
48. B. It takes Lan 3 hours a day to do her homework.
- The structure "It takes + time + to + verb" is used to express how long something takes.
49. B. Nick felt stressed from schoolwork; however, he told this problem to his teacher.
- "However" is used to introduce a contrasting idea. Nick felt stressed, but he took action by telling his teacher.
50. D. Unless you learn online, you won’t understand the lessons.
- "Unless" means "if not." The sentence implies that learning online is necessary to understand the lessons.
I hope this helps! Let me know if you have any other questions.