passive forms

1. millions of lives have been saved by clean water and sanitation.
2. most science festivals are managed by a leading institution, often a museum or a university.
3. that festival was held by a group of more than 500 scientists, researchers, performers and intellectuals.
4. our lives will be improved by the recent advances in medicine.
5. when had the new software been installed by the it specialist?
6. simple kitchen experiments can be done by people of all ages.

active forms

1. clean water and sanitation have saved millions of lives.
2. a leading institution, often a museum or a university, manages most science festivals.
3. a group of more than 500 scientists, researchers, performers and intellectuals held that festival.
4. the recent advances in medicine will improve our lives.
5. when had the it specialist installed the new software?
6. people of all ages can do simple kitchen experiments.