Question

1. Yesterday they had a party(Past Simple) 2. Yan wrote a letter to Nick two days ago(Past Simple) 3. She was cooking from two till four o’clock yesterday.(Past Progressive) 4. Two days ago my friend and me saw an UFO(Past Simple) 5. She has returning just from Italy.(Present Perfect) 6. They have done already their homework.(Present Perfect) 7. They have bought just some postcards.(Present Perfect) 8. She cooked dinner yesterday. (Past Simple) 9. Pete was watering flowers in the garden at 5 pm yesterday. (Past Progressive) 10. I has been never to the USA. .(Present Perfect) 11. Nick’s uncle went to Russia 3 years ago. (Past Simple) 12. I was reading a book from 3 till 5 yesterday. ( Past Progressive) Всё ли верно?

Answer 1

5. Has returned 
10. I have never been to

Answer 2

1. Yesterday they had a party - Вчера они устроили вечеринку. (Past Simple) 2. Yan wrote a letter to Nick two days ago - Ян написал письмо Нику два дня назад. (Past Simple) 3. She was cooking from two till four o’clock yesterday - Она готовила с двух до четырех вчера. (Past Progressive) 4. Two days ago my friend and I saw a UFO - Два дня назад мой друг и я увидели НЛО. (Past Simple) 5. She has just returned from Italy - Она только что вернулась из Италии. (Present Perfect) 6. They have already done their homework - Они уже сделали свою домашнюю работу. (Present Perfect) 7. They have just bought some postcards - Они только что купили открытки. (Present Perfect) 8. She cooked dinner yesterday - Она готовила ужин вчера. (Past Simple) 9. Pete was watering flowers in the garden at 5 pm yesterday - Пит поливал цветы в саду в 5 вечера вчера. (Past Progressive) 10. I have never been to the USA - Я никогда не был в США. (Present Perfect) 11. Nick’s uncle went to Russia 3 years ago - Дядя Ника уехал в Россию три года назад. (Past Simple) 12. I was reading a book from 3 till 5 yesterday - Я читал книгу с тремя до пяти вчера. (Past Progressive)

Да, все предложения верны с точки зрения времен глаголов.