1. He last went to see his grandparents a month ago.
--> He has not
2. They haven't visited Nga for half a year.
--> They last
3. The last time T came here was 10 years ago
--> I haven't
4. The last time I saw Dick was in 1995.
--> I haven't
5. Mary has been working in this company for five years.
--> Mary began/started
6. No sooner had we finished the test than the bell rang.
--> Hardly
7. Hardly had they arrived at the airport when it began tp rain.
--> No sooner
8. I have never met a famous person before.
--> This is
9. This is the first time she has seen this man here.
--> She has not
10. This is the first birthday time she has attended such an enjoyable birthday party.
--> She has
11. They spent two hours doing these exercises at home.
--> It took
12. If you don't have a rest, you really will be ill.
-->Unless
13. You won't lose weight if you don't stop eating much.
-->Unless
14. Unless he phones immediately, he won't get any information.
--> If he
15.you can't visit London unless you get a visa.
--> If you
16. She works hard, so she earns a lot of money.
--> If
17. I didn't send her an invitation because I didn't find her address.
--> If I had
18.We got lost because we didn't have a map.
-->If
19. Without his help,we would all have died.
--> If it
20. I would like to go fishing,but I don't have much time.
--> If I had