Here are the correct words for each sentence:

4. The news about the COVID-19 Coronavirus **has** been updated.
5. My father or my grandparents **are** coming to the train station.
3. A packet of flour and a dozen of eggs **were** on the table.
6. Mumps **is** a very contagious disease.
7. A ship and a plane **have** recently disappeared without trace.
8. Politics **is** something I'm not interested in much.
9. Nike, together with other famous sports brands, **has** sponsored the marathon race.
10. My mother, not my father, **comes** to the parent meeting every year.
11. Either book **is** good, you can choose which one to read.
12. The police **are** investigating the bank robbery.
13. One of my sisters **works** at a very famous shopping center.
14. Two weeks **is** not too much waiting for the results.
15. Scissors **are** dangerous for very small kids.
16. Doing aerobics **is** a good way to keep fit.
17. Not only the doctors but also the patients **agree** with the treatment.
18. The Stars and Stripes **is** the name that the Americans give to the flag.
19. A number of women standing there **are** my neighbours.
20. The poor **were** distributed enough food.