Question 5. When the police came, the thief was running on the roof of the house.
→ B. was running (Past continuous tense to describe an action in progress at a specific time in the past)

Question 6. Nam: "What about using Internet to play this game?" - Tuan: "Yes, good idea."
→ A. good idea (A natural response to a suggestion)

Question 7. This test is easier than what we thought.
→ D. easier (Comparative form)

Question 8. He saw Bill Gates on T.V., whom he admired so much.
→ D. whom (Used for people, as the object of the verb in the relative clause)

Question 9. If Alex looks up the word in the dictionary, he will know the meaning of it.
→ A. looks / will know (First conditional: present simple + will for future result)

Question 10. Bun Cha, Pho, Hu Tieu are examples of famous Vietnamese speciality.
→ D. speciality (Traditional or unique food from a specific area)

Question 11. The road is narrow, so much traffic congestion often occurs at rush hour.
→ B. much (Used with uncountable nouns like "traffic")

Question 12. The dust may badly affect our eyes when we travel every day.
→ D. eyes (Dust primarily affects vision or causes irritation to the eyes)

Question 13. Regular exercise is essential for maintaining good physical and mental health.
→ C. exercise (Exercise is key for health)

Question 14. A counsellor can help you manage stress and provide guidance in difficult times.
→ A. counsellor (A person who offers advice or guidance)

Question 15. Eating a healthy diet helps you stay fit and full of energy.
→ C. healthy diet (A balanced and nutritious food intake)

Question 16. It’s important to manage your time effectively to balance work and leisure.
→ B. manage (To handle or control something efficiently)