encuentre el error en las oraciones y ponga la correcta. DOY CORONITA :(

4. The letter was sent today
5. The lectures are attended by all the students
6. The helicopter is piloted by my dad
7.The flowers were watered today
8.The keys were lost yesterday
9. The tests are written every month
10. The car was repaired three days ago
The letter are sent today, send does not have a tilde
The lectures is attended by all the students, the students do not go to the lectures
The helicopter are piloted by my dad, it is not piloted if it does not pilot.
The flowersflowers was watered today, irrigated with tilde
The keys was lost yesterdat, lost goes with tilde
EXPLANATION:
I HOPE I HAVE HELPED YOU.