Here are the suggested answers to fill in the blanks:

5. I’m sorry. (I not finish) **didn’t finish** this work yet.
6. He used to (take) **take** his sister to school by his mother.
7. They (live) **have been living** in that house since it (build) **was built**.
8. Last night my father (arrive) **arrived** home at 10:30 PM. He (have) **had** a bath and then (go) **went** to bed.
9. Did you (visit) **visit** One Pillar Pagoda when you were in Hanoi?
10. The telephone (invent) **was invented** by Alexander Bell.
11. She often (take) **takes** to the theatre by The Greens.
12. If you (not learn) **don’t learn** the lessons carefully, you cannot do the test well.
13. The teacher asked why she (not do) **didn’t do** her homework.
14. We are looking forward to (see) **seeing** you.
15. It took me 2 hours (do) **to do** this work.
16. They spend all morning (learn) **learning** their lessons.
17. Don’t forget (post) **to post** my letter.
18. When, (do) **did** you (start) **start** learning English? – Two years ago.
19. We (go) **are going** for a picnic next week.
20. I can’t go out because it (rain) **is raining**.
21. She (take) **will take** a trip to Halong Bay next month.
22. Wearing uniform (help) **helps** students (feel) **to feel** equal in many ways.