1. Не was abroad five years ago. 2. Were you in the Caucasus last year? 3. They left England when he was still a child. 4. He hasn't come back. 5. Has he gone already? 6. When did you see him last? 7. I haven't seen him for ages. 8. His health has improved greatly since I saw him last. 9. Last night I felt tired and went to bed very early. 10. Where did you spend your holidays? 11. Have you ever spent your holidays in the Crimea? 12. While travelling in the Crimea I met your friend. 13. I have never visited that place. 14. He visited that place last year. 15. I have just got a letter from Tom. 16. Did you take any photographs while travelling in the south?
Have known
Ты бы не сказала «Я знал её 6 лет»,
Я знаю её 6 лет» - это правильно,
Правильнее говорить в настоящем времени