Rewrite the active sentences in the passive.
1. alexander fleming discovered penicillin in 1928.
2. mr. roberts teaches our class on tuesdays.
3. leonardo da vinci designed a helicopter in the 15th century.
4. we keep the laboratory door closed at all times.
5. anna lost all her files when her laptop crashed.
1. Penicillin was discovered by Alexander Fleming in 1928.
2. Our class is taught by Mr. Roberts on Tuesdays.
3. A helicopter was designed by Leonardo da Vinci in the 15th century.
4. The laboratory door is kept closed by us at all times.
5. All files were lost by Anna when her laptop crashed.
Объяснение: