1.They are building the apartment houses.
2.Tolstoy wrote Anna Karenina.
3.They have sent for the doctor.
4. People play tennis all over the world .
5.They will wallpaper the room tomorrow.
6. They always listen to him with great interest.
7.They have spoken about this student recently.
8. As soon as my parents come back from vacations, they will make the repairs.
9. They answered a lot of letters.