Ответ: поставив глаголы в Present Perfect или Past Simple1.
How long have you known him? — I (have known) him since 1984. He ( lived)
in Moscow for two years and then (went) to Siberia. 2. When did he (
arrive)? – He ( arrived) at 2 o’clock. 3. I (read) this book, when I
(was) at school. 4. I can’t go now. I (have not finished) my work. 5. Have you
( had dinner yet? 6. The lecture has just ( begun). You (were) a
little late. 7. We (have missed) the tram. Now we have to walk. 8. Have you (
been) here before? – Yes. I (spent) the last holiday here. 9. Did you (
see) Kitty on Monday? – No, I (have not  seen) her this month. 10. Where was Tom? – I (did not know). I (have not  seen) him since last night. 11. I
(have  lost) my pen. Did you ( see) it anywhere? 12. Have you ever ( tried) to
give up smoking? – I (have tried) several times but failed. 13. Why did you (
switch) on the light? It (was) dark yet. 14. When did it ( happen)? – I
( thought) last weekend. 15. He ( left) for the Far East two years
ago and I (have not seen) him since. 16. The last post (has come). I (
expected) a letter from my cousin. 17. Have you (fouind) the key which you (
lost) yesterday? – Yes. I (found) in the pocket. 18. I (saw) him
in the library this afternoon. 19. I (have make) a mistake, I want to rub
it out. 20. Can you give me the textbook? – No, I (left) it at home.
21. Have you  seen pictures by Picasso? – Yes, I (saw) them not long
ago. 22. Have you ( been) to St. Petersburg? – Yes, I (was) there last
winter. 23. Have you ( done) the translation? – No, I (have not finished) yet. I
(began) it 20 minutes ago. 24. When did you ( come) to Moscow? – I (
arrived) this morning.