7)
1.Conan Doyle used to write historical novels, but became popular because of dectectives.
2. Professor Black studied (or explored, на ваш выбор) deserts before, he knows a lot about animals that live there.
3. I used to read only fantasy and fairytales, now I like adventure literature.
4. When I came to my grandma, me and my friends played in big cave.
5. What's wrong? You look upset.