1. The doctor has seen us there.
2. Mary will have put the salad on the plates by 6 o'clock.
3. Nick had brought some water when we came into the house.
4. They have just eaten all the cakes.
5. He has brought a box of chocolates for her
6. Someone had opened the window when we entered the room.
7. the pupil-on-duty will have cleaned the blackboard by the end of the lesson.
8. My sister has already cleaned the floor .
9. My mother has just opened the door
10. We has recently bought this tape-recorder.