VI.
21. d
22. c
23. c
24. b
25. c
26. b
27. c
28. a
VII.
1. In
2. Journey
3. Advance
4. And
6. On
7. Buses
8. End
9. Same
10. Last
X.
1. If Susan ate too much chocolate, she would be overweight.
2. We were extremely tired after the trip so we slept on the bus on the way home.
3. Lan asked Viet if she could lend his ruler.
4. The living room is being painted at the moment.
5. Tet is an important festival which occurs in late January and early February.
6. I wish I were on the beach with my friends now.
7. Yesterday you promised to carry on shooting the film.
8. It is a rainy day so we will stay at home to read book or watch TV or do other things.
9. It is difficult to arrange a day which is convenient for everyone.
10. Because of working hard, he passed the examination.