Если по примеру, как здесь, то - They are cows.
Но я бы лучше ответила по другой конструкции, так как корова будет третье лицо в английском. - It's a cows.
1. The doctor ordered the man to take the medicine.
2. The actor told him that he will not answer his question.
3. He told her that he will phone her next week.
4.Tom asked me is I know where he have put his hat.
5. The little boy asked his parents what they have bought him for Christmas.
6. Mother told her son to go to his room and do his homework.
7. Her boss told that she will be paid twice a month.
8. He asked Nick when he flew to the USA.
9. Mary asked her sister if he is sleeping or reading now.
10. She told Ben not to go near the fire.
11. The teacher asked the boy if anybody helps him.
12. Dad told us that Ann was born in 1998.
1.+My friend was at the party yesterday.
-He wasn't at the party yesterday.
?Was my friend at the party yesterday?
2.+He visited me last week.
-He didn't visit me last week.
?Did he vizit you last week?
3.+Ann went to the country by car.
-Ann didn't go to the country by car.
?Did Ann go to the country by car?
С каким заданием...........................?