Are these sentences correct? Correct them if they're wrong. All sentences are in the past simple, active or passive. Правильные ли эти предложения? Исправьте их, если они неправильные. Все предложения в past simple, в активном или пассивном залоге.
1. What was happened?
2. The mountain vanished.
3. The fog appeared.
4. The building destroyed.
5. The flowers were died.
6. The dirt was disappeared.
7. The answer emerged.
8. The door opened.
9. The tram was arrived.
10. The film started.
11. The window was closed.
12. The toy was broken.
13. Interest rates were lowered.
14. The house built.
15. The ice melted.
16. The river froze.
17. The cake was risen.
18. The events were occurred.
19. The vase fell.
20. The tower demolished.

Answers
1. What happened?
2. Correct.
3. Correct.
4. The building was destroyed.
5. The flowers died.
6. The dirt disappeared.
7. Correct.
8. Correct.
9. The tram arrived.
10. Correct.
11. Correct.
12. Correct.
13. Interest rates were lowered.
14. The house was built.
15. Correct.
16. Correct.
17. The cake rose.
18. The events occurred.
19. Correct.
20. The tower was demolished.