12. Lan goes to her office in 10 minutes by walking every day. Lan....... 13. Nga spends 2 hours cleaning her room every weekend. It ...... 14. It was afour -hour-flight from Ha Noi to Tokyo It takes...... 15.We spent 2 days visiting Cat Ba Island last summer vacation. It .......... 16.Ba used to spend 2 hours a day to practice speaking English. It used to......... 17. My sister often runs 3 kilometers in 7 minutes. It often...... 18.I ride my bike to school in 20 minutes every morning. It ....... 19.Bac spends1 hour playing badmintonwith his friends every afternoon. It ......... 20. It took mel hours to do my English homework last night. I....... CI