Find and correct the mistakes in the following sentences.
16. Robots now can be helped astronauts perform very difficult tasks.
Correction: _______________
17. Can robots recognize our voices five years ago?
Correction: _______________
18. Sorry, I can’t help you. I must make my homework!
Correction: _______________
19. I have read the book three times, but I can understand it.
Correction: _______________
20. Mozart could play piano when he was only five years old.
Correction: ________________
16. Robots now can be helped astronauts perform very difficult tasks. Correction: _______can be=>can________
17. Can robots recognize our voices five years ago?
Correction: _____Can=>could__________
18. Sorry, I can’t help you. I must make my homework!
Correction: ____make=>do___________
19. I have read the book three times, but I can understand it.
Correction: ______can=>could_________
20. Mozart could play piano when he was only five years old.
Correction: ______piano=>the piano__________