21. Life on another planets might be found.

22. All schools have to be improved in the city.

23. This exercise must be done carefully.

24. The problem can be solved

25. Experiments on animals should be stopped

26. .l won't be told the truth about the situation

21. We might find life on another planet.

Life on another planet might be found.

22. We have to improve all the schools in thecity.

All the schools have to be improved in thecity.

23. You must do this exercise carefully.

This exercise carefully must be done .

24. We can solve the problem.-

The problem can be solved.

25. People should stop experiments on animals.

Experiments on animals should be stopped .

26. He won’t tell me the truth about the situation.

I won't be told the truth about the situation.